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MG MGB GT V8 Factory Originals Technical - 78 B 350?

I am interested in putting a large motor in my 78 b and i like the idea of the rovers but i am not looking to completely rebuilt the motor due to the fact that there is plenty of other things i need to get done on it. The question would be is it possible to buy a chevy 350 small block crate motor and get it in? if so how much modifcation will be required
Any info would be much appreciated
David Livingston

Just wondering if you have considered an LS1/t5 combo? You see them all the time on Ebay, and hp to weight ratio can't be beat. Most of them are going for less than a lot of crate motors are bringing. Just would like someone do it...I am too poor so am sticking to a little Ford 4 banger.

G.P. Copes

David, you can do anything you wish to be perfectly honest. Though I would recommend finding a motor that can be lightned up a bit more and fits without major cutting to the body and firewall. The 302 fits right in with minial cutting and will give you more power than a MGB can ever put to the ground without major rear bodywork and a set of big slicks..

Check my site for some more info..
Larry Embrey


Go to this site:

I have contacted most of them about the small block swap and they have been more than willing to answer questions.

On another note, according to that page the SBC is externally the same size as the rover engine. And it is possible to get a small block to weigh a lot less (aluminum and grind a little off the block).


....&, by the time you do the aluminum heads, aluminum billet flywheel, block lightening, etc to get the Chevy 350 down in weight so it doesn't cause the car to have horrific nose down attitude, understeering, and general erradic handling tendacies you could've rebuilt a Rover engine! I've only driven 1 MG with US cast iron in it & got out sweating because I wasn't sure where it was going to go...
anthony barnhill

Only if you farm out all of the work and don't complete it yourself. However I get the impression that most people on the list do their own work. I know of a particular BV8 with a ZZ4 (yes I know the ZZ4 is expensive, but it is possible to build something similar to that motor for far less) that combined weight is 2500 lbs 1260 front and 1240 rear. And I must say that the car looks very good (ie no hacking, outlandish hood bulge or cobbled together).


My V* car is going to come in right at or below 2,000 pounds!!!
anthony barnhill

Zach, how the heck did they get the tail to weigh so much, was it a GT?? Mine weighs in 2420 total, 1180 rear and 1240 front. That is with Cast iron 302 with Alum heads and all alum acces (which is normal for any decent 5.0..) I wish I had more rear weight as it would help keeping the tires planted!!

Best o luck with that, though if you do a rover it should not be a problem.. I could go alum 302, but that is another $3500 and only saves like 50lbs tops..
Larry Embrey


Yes the car is a GT. He said that the only mods (other than engine) that he has done to the car are the addition of tube shocks. He is still running the stock rearend even (I was surprised).

After several email responses from the owner of the car, I am now seriously considering the small block swap. I already have the ZZ4 short block.


Why not use the Rover and put a blower on it? I'm pretty sure it could be made to fit under the hood. Of course that would take a custom intake but that's not such a big deal. I've looked at the prospect pretty closely and I think it can be done.
Jim Blackwood

Back when I was taking calculus in college (ok ok, 3 semesters ago) We spent a lot of time studying diminished returns, and how to mathmatically determine the most profit with the fewest number of products made. For todays purposes we'll say profit is useable power at the wheels + fun, and products made is modifications to the car and driveline. At what point do we reach the level of diminished returns? Once those wheels start spinning freely on the pavement, all the extra horsepower you have is worthless. My rover 3.5L V8 spins the tires pretty quickly in 1st gear with stock suspension and a stock mgb rear end. Steve Carrins 370 hp 302 V8 with an ultra low rear axle (2.72 I think he said on Sunday) still spins the rear wheels. And Larry Embrey said the biggest thing keeping him from a lower 1/4 mile time was keeping the tires on the road. Yeah, the fun factor is cool, and having something unique is just as cool, but this still brings us back to diminished returns, and the question of whether a 350 sbc is a worthwhile conversion. I'm gonna go with no. There's too much work involved for what you'll get with an easier conversion anyway.


p.s. Rover V8 are cheap and plentiful if you look in the right places, and rebuild shouldn't be that expensive either.


(to avoid a potential flame war, which I seem to get into all to often on this BB, please assume the following comments are meant in good spirit - they are)

Your comments seem to imply three things:

1) that there's something rational about what we're doing
2) that the primary (or only) use for more power is for drag racing
3) That it's significantly harder and costlier to install (properly, of course) a SBC or a Ford 302.

My opinion?

a) While you may get diminishing profits (usable power and fun) as you increase production (modifications), you still get profits. Even so, wheelspin on take off is only part of the measure of profit. By almost all other criteria, returns don't start to diminish until you get into the ridiculous range of power. And then only because of the lopey engine idle. If I could get a smooth running, tractable, engine with 700 HP into my MGBGT or my TR6, you betcha I'd do it. Whether I could use all of it or not. Not rational, but's what I'd want.

b) I can't argue with you that when the wheels spin, more power is useless, but the wheels don't spin after you've gotten up to speed. Getting from 30 to 75 is a lot faster with more power, and until you get a LOT more power, wheel spin in that speed range is not a problem. Even if the tires do spin in the quarter mile, a 375HP car will still beat the same car with only 200HP to the finish line. If you're really into drag racing, you'll want to use slicks and modify the rear suspension to lessen wheel spin anyway.

c) In general, it costs a lot less to get the same amount of power from a SBC or a Ford than it does for a BOP/Rover. Installation is not a great deal more difficult either. There is a weight penalty with the SBC or the Ford, but with the Ford, it is a small penalty. About 25 pounds or so. Steve's car weighs around 2300 pounds, so with 370HP, that's about 6.2 pounds per horsepower. Four horsepower is lost to offset the extra weight from a performance standpoint. I think 4 out of 370 won't be missed much. With a Ford axle, you will add at least 25 pounds to the rear, so your weight distribution is either unchanged or improved. A SBC will add more weight, but I don't have reliable numbers for that. A few minor suspension mods, and all is well in the handling department.

There's no question that the BOP/Rover is an easier installation, but only because it has been done so many times that all of the problems have been sorted and conversion parts are readily available. Regardless of how cheap and plentiful Rover V8s are, Fords and Chevys are more plentiful and cheaper. I predict it won't be long until the Ford becomes the engine of choice, as conversion info and parts become more readily available.

I've never driven a SBC powered MGB, but I have driven a TR6 with a 350 Chevy. I can tell you that car drives and handle every bit as well as my stock TR6, and my stock TR6 is in good condition. I have driven two Ford powered MGBs, with the same comments - they both handle as well as my stock MGBGT.

I'd like to make a small wager. Drive Steve's car, and then tell you don't want one just like it. I'll bet you do. If you don't, lunch is on me. I haven't driven Larry's car, but I'll make the same wager.

None of which matters anyway. If we tried to quantify this hobby, we'd all probably take up stamp collecting - I'm sure the monetary returns would be greater. I say go with what floats yer boat. The upcoming issue of the newsletter will feature an MGB with an Olds Quad-4 engine - definately not mainstream, but still pretty cool. A lot of folks think we're crazy (or worse), and see no reason for more than 95HP in an MGB. Who knows, maybe they're right. Nah. They're wrong.
Dan Masters

No offense taken by your comments at all, and this is DEFINITELY NOT a flame war.

I tend to agree with you on most every point you've made, and I think I tried to bank my comments more towards a street car as opposed to drag racing, but it may not have come out that way. There are so many ways to look at these conversions, and I don't think any one way is more or less 'right' then another, just different.

1) There isn't very much rational about what we're doing, but is there a grey area between rational and exorbitant? I'd like to hope there is, and that's where I try to shoot for when doing these projects.

2) You can only accelerate as fast as the guy in the lincoln in front of you, so it seems that when we get up into the high power cars that yes, it is just for drag racing, barring isolated incidences such as no traffic, or highway cruising. (Which never happens in Metro Detroit...hehe)
3) I've seen GORGEOUS 302 conversions that made me drool (Steve's car) and I've seen cars be completely bastardized too. All the pics of sbc's seem to fall somewhere in the middle, more leaning towards heavy modifcation of the car. Maybe I'm seeing the wrong pics?

I have to agree, it is WAY cheaper to get more power out of the 302 or sbc then the rover. I think the 5.2L rover with 400 hp starts around $13,000.... that's just stupid and wasteful.

So let me try restating my opinion in a little better way: For a street car, driving day to day in nice weather, in traffic, with the occasional lighting it up at a light, and maybe taking it to public night at the drag strip once a year, is a sbc going to do anything differently then a 302 or a rover? Maybe not. Will it require more work to do the exact same things given those parameters? I still think it will.

Once all bugs are out of the 302 conversion, and it becomes more popular, and more "easy" (no more wheel reinventing) then sign me up! 370 hp in a B with an ultra low gear ratio so you can still floor it when you want, and cruise on the highway at super low rpm's... isn't that the ideal for a daily driver car?

I would LOVE to drive Steves car, and hell, I'll buy him lunch if he'll let me!

It's great to have different opinions, and different view points, it really does open up new ideas, and new perspectives, and we all benefit from it. I'll never get in a flame war because someone has a different idea or view point. I'm more mature then that.

Welcoming other view points and opinions,


More HP than needed to spin the wheels is useless??? I resemble that comment...;-) Actually it's not. It's all in how you get there. Having toyed with 215's in NA, cammed, turboed, and blown configs all in the same MGB I can sincerely say that the *only* substitute for cubic inches is a positive displacement blower. And even that falls a tad bit short in certain spots. So in my NNHO the ideal solution is the aluminum block SBC at about 383 and a moderate state of tune. Guaranteed to get your attention. And then maybe a blower...
Jim Blackwood


Above you stated "Rover V8 are cheap and plentiful if you look in the right places, and rebuild shouldn't be that expensive either."... can you elaborate on this a bit. I've always found that they were next to impossible to find over here, and they cost way too much getting them from the UK.

This interesting discussion has made me think differently about my own conversion. My motor is from a ’63 Buick Skylark 215 that the factory rated at 200 bhp. Due to the whopping amount of wheel spin I could see no reason to want more. In reality though I don’t drag race so that doesn’t matter. The joy I get in driving doesn’t come from off the line, but at speed around 2500 to 3500 rpm. Powering through curves, shooting into tight spaces and passing annoyingly slow cars are things a stock MGB does well, but a V8 conversion does better. Tire spin wouldn’t be any more of a problem with an additional hundred horsepower in these more typical sports car driving activities, but it just might add that much more excitement. It is much nicer to be able to pass a car that’s traveling 50 mph in just a few seconds rather than following for five miles before there’s a long enough brake in oncoming traffic to allow a fifteen second pass.
George Champion


I paid $350.00 for a long block 3.5L V8 from a 1988 range rover through the rovers north bulletin board system. The last time I looked on I saw a 3.9L short block for $250.00 and heads can be had for as cheap as 175.00 US each Not *horribly* expensive, and you can use the buick 215 internals to rebuild the motor (bearings, timing chain, etc etc) My philosophy is if I go to someone looking to sell and make a profit on the motor, I'm gonna pay more for it, but if I can find someone who needs to get rid of it, I'll do much better. For instance, my motor was taking up garage space for someone who put a 350 sbc in his truck (funny how coincidental that is LOL), and he was more then happy to get it out of his way.

Don't hesitate to ask if you have any other questions about the rover motor, or rebuilding them, I'm more then glad to help anyone in any way I can.

David Livingston: you said there were other things that had to be done to the car in addition to the motor swap you're looking at. Will you elaborate on that? A motor swap in a car needing body work can get you in a LOT of trouble...



You said what I was trying to say, but you said it better. In the type of driving where these cars typically live, 375HP is not too much.


Steve is easy - just offer to buy him dinner at his favorite Chinese restaurant and he can be had. You live in Indiana, right? That's not far from where Steve lives in MI.

Just to add a little more fuel to this fire:

A brand new Ford GT40 375HP engine will cost around $3,000. Another $1,000 or so should be enough to finish it - intake, carb, starter, etc. Less if you're a good scrounger. 375HP for around $4,000.

For another $2,000 or so (maybe more, but not exhorbitant), you can get a stroker kit to bring the 302 up to 347ci. That's into Chevy 350 territory. These 347ci Ford engines have been dyno tested in the range of 475 - 500 STREETABLE horsepower! And that's before the adddition of a supercharger! (note to Jim Blackwood - there are a large number of companies offering complete supercharger kits for the Ford engine, all at reasonable costs).

All the power, reliability, and easy availability of parts of the Chevy, only a bit more weight than the stock B engine, and all this at a reasonable cost!?!?!?!? What's not to love?
Dan Masters

Dan has it right. The only thing I could see as a hamper on his 500+ hp supercharged car is keeping it under the stock, hood, BUT We will see what I can cook up this winter.

Thanks for the vote of confidence on my car :-P She is quick but handling is ATTROCIOUS, the springs are all tired, the back perch pads are shot and I have no front swaybar, YUCK!! It handles like, like.. A sunbeam tiger!! DOH! That and I tore the rear end out of it at the drag strip, OOOPS!! I will be doing a Ford 8.8 over the winter and some 205's at least on the back, so next year I hope to be low 13's maybe even 12's if I can get it to really hook..

Did I hear that steve is running 2.72 gears in his axle?? how does that work, that would be a touch too low from the calc's I have seen, I am shooting 3.27 or maybe 3.08 based in 1/4mile mph and my motors RPM range.. will put me in the 1600-1800 rpm cruise on freeway!!
Larry Embrey

More fuel is good!
I like the 302, I thought it was a wonderful engine when it was a 289 and it's just gotten better. I've seen what it can do too, having traded cars for the evening with a buddy who had just dropped a built-to-the-max 289 into his '63 Mustang back in the early '70's. Saturday night in Dover was never so fun! I also like Ford's SEFI/EDIS really well. More on that once I've got the car insured. Well, OK Dan you're into about the 5-6 grand range with your stroker, and all I'm saying is that for real close money an aluminum 383 or at the very least a 350 should be in reach. Don't see that fitting it in should be any real big deal either, so if I was looking at a new swap that's the route I'd try to go, partly for weight/HP/availability, partly for displacement, and partly for avoiding the crossmember trim job. HP figures being what they are I see no point in arguing them, but cubic inches are hard to ignore. Oh, and I think somebody was telling me there's a blower kit out for the SBC. That'd be fun.
BTW Dan, things were sort of a blur at the V8 meet. I figure we met but there were so many new faces and interrupted introductions, and I'd really been aiming to get a chance to talk. Sorry 'bout that.
Jim Blackwood





Yes, Steve is running a 2.73 rear axle, but it still pulls STRONGLY of the line. He's using a 225/15 tire, but I don't know the aspect ratio - 50, I believe. If it's a 50 series, then 70mph is 2692rpm in 4th. If it's a 60 series, then 70 is 2506. I talked to him on the phone yesterday, and he is going to go to a lower gear - 3.2 or so - when he puts in the Ford 9" axle later. I'm going to be running a 3.54 with the Jag IRS, and 215-60-15 tires on my MGBGT, which is 3311 at 70. In 5th, its 2086 at 70. That seems about right to me. Since I'm going to flare the rear fenders anyway, I may go with a wider tire, maybe a 245 or so.


I helped you unload your car off the trailer, but your car drew such a crowd that I didn't get a chance to talk to you. I stayed with friends in Wayland, rather than at the host motel, so we didn't get a chance to talk later either. Maybe next time. If you can get an aluminum 383 Chevy for the same price as the Ford 347 - go for it! If money is no object and it costs more, go for it anyway! I don't have much patience with brand loyalty. You're right, it won't be much more of a problem than the Ford to install. The Chevy is about the same size externally as the BOP/Rover. You're right again, there are blower kits available for the SBC. Heck, why not go with an aluminum Chevy big block if your wallet can stand the hit! There is an MGB with a Chevy 454 on my web site - It looks good!


Here are the actual cost figures for the Ford engine in my TR6.

1. Engine: I paid $2,800 for mine, but the current list price in the 2002 FoMoCo catalog is $3,195.

2. Intake - $250 for a dual quad. current price for a single 4bbl, dual plane Edelbrock is $180.

3. Carbs - 2 400cfm @ $200 each - $400. A single 600cfm Edelbrock is around $220. Your Demon carb is more - $300?

4. Oil pan - taken off a junk Ford engine and modified - $0.00

5. Timing cover - bought at a swap meet - $10

6. correct rotation water pump - $98

7. water pump pulley - found in my parts stache from a 77 Buick - $0.00

8. Crank pulley - machined from a piece of scrap steel on a friend's lathe - about $1.00 for the steel

9. Distributor - Accel electronic - $195

10. Motor mounts - homemade out of scrap steel, and purchased rubber isolators - $20

11. Exhaust - custom made from a set of block huggers - around $200

12. Remote oil filter kit - $35

My total cost? $4,009. If you stick with a single carb, the current cost for a 302 should be around the same or less, depending, of course, on how much you can scrounge.
Dan Masters

Dan, those numbers for the 302 are about what I ended up with I think I had $4200 when done.

HRMM, I got a set of 3.08' and a set of 3.27's ready for when I get the ford 8.8 rear. I will likely start with the 3.273's as that is a big step down from the 3.909's i have and based on calc should put me right at around 105mph at the peak of my rpm range in 4th, which is perfect for the track, and it will open up 1st gear for me as well..

I am also going to be changin my water pump out this winter I found a short std rotation pump I will buy that will let me mount a big 16" elec puller fan and put the front swaybar back in!! next summer should be a blast!!
Larry Embrey

Something else to think about, you won't need peak HP at peak MPH. That is, unless you create heck of a lot more aerodynamic drag than the car already has. That means if you peak out earlier you'll still have the power to achieve top speed but will get there quicker. Considering most HP curves do not drop off precipitously after the HP peak, you could easily have usable power all the way to redline in top gear if proper gearing is chosen. The risk then becomes one of over-reving the engine. I'll admit, I love the sound of a high winding engine, and I've had the broken pistons and spun bearings to prove it, but there's just nothing quite like 150 at 6-7 grand, and I really don't care to go any faster than that unless it's in an airplane.
Jim Blackwood

Jim, good thoughts there.. What, I am talking about peaking my motor at the speed I should be crossing the 1/4 mark. I know my motor goes away around 5500rpm, I mean GOES AWAY, floats valves loses power etc. That is because I have a super mild cam and valve spring in the car, she is a daily driver and I was trying to pass emmissions.. WAS operative word, now that that is over I may jump to a "lumpy" cam heh. I know my car pulls 102 when using 5th for the last few hundred feet of the 1/4mi, so I upped that to 105 and then am setting gearing so that 105mph in 4th is just under were she goes away..

That way I can stay out of OD and leave my foot on the mat through the line heh also in this step will be posi and 205's under stock bodywork, total sleeper is my goal, nothing exterior to give away her attitude.. I am hoping to get my 60ft drag times down under 2.1sec, that will put me VERY close to 12 sec runs!!

FYI this sets me at 170 in 5th @ 5000rpm.. which I think is just plenty heh, I mean it is only 2.5x the max legal speed limit heh
Larry Embrey

OIC, yer building a drag racer! I didn't quite catch that fine point. Well I certainly want to follow your progress on that. BTW, on the subject of cams, go slow, those hot bump sticks will ruin you. The power is an ultimate seduction and despite all your needs to have a streetable car you will never again be happy with anything short of the hottest engine you've ever had in it. Ask me why I progressed from hot cams to a turbo to a blower! I actually attempted to tone things down a bit, that was an effort doomed to failure. The car has the power now, but once I'm driving it I suspect I'll be looking for valve springs to get the revs back up. That and stronger pistons for the stroker motor in the basement.
Jim Blackwood

Well, I am not building specifically a drag car, well that is not true I am toying with a MGB GT drag only car, but that is WAY off. But legally it is the only place I can afford to go REALLY FAST in my car, so I am making sure she is fun in that arena, plus the gearing "just happens" to put me in a good highway cruise range.. I have dreamed of forced induction, but a blower takes to much room up front that I have none of and a turbo just makes the hot engine bay a furnace.. Nice thing about turbo is I could probably cook my steaks on the hood after the drive home!!

JIM, good points again on the cam.. I want to jump to a 280grind cam, desktop dyno shows a 40+hp increase from just a cam, but I worry about losing streetability, so may hold off a while on that, till I can get the power I have down to the road.

With most american people they equate speed with 1/4mi anyway, it is the standard measurement of speed that is universal acrost the US. So I use it as a way to further promote interest in these cars, eyebrows really raise when you say you have a 13sec daily driver..
Larry Embrey

Quarter mile times certainly make more sense than the normal European claim of how fast they can go in each gear, and you wonder "and this proves exactly what, and where does it put you in a race?"
George B.

I just have a Rover 4.2 -- nothing exotic like you guys with 302s and so forth -- but I was persuaded to try installing a fairly high-lift cam (let's call it a "very fast road" unit), along with stiffer double springs that compress more compactly (you can only go to .370 lift with the stock springs and this cam's about .490) and I personally think it's been the greatest change since sliced bread. The new cam was designed for upper-rpm performance, but I advanced it slightly to get a little better bottom end, and you still get that really fat bottom with incredible top-end. The car absolutely screams now, all the way up to about 6K rpm where my rev-limiter kicks in. It's a real pain to get to the cam in a pushrod engine jammed into a tiny engine bay but it's well worth the effort.

heh I am already eying a better cam, but need to balance it with divability and other tuning issues.. That may wait intill NEXT winter, but we will see how things develop.
Larry Embrey

This thread was discussed between 10/09/2002 and 16/09/2002

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