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MG MGB GT V8 Factory Originals Technical - Engine and Gearbox Mounts

Does anyone know the part numbers for the engine mounts required for a rover 3500cc engine fit to a RB MGB, And the cotton reel gearbox mounts for fitting the LT77 gearbox?

Thanks in advance

GLG Lavis

No - but any MGB supplier worth their salt can get you the engine mounts you need - the V8 ones are identical to the standard rubber bumper ones but much more heat resistant. Make sure they know it is for a V8. Try watford classics on ebay.

I just bought some gbox mounts from Clive Wheatley today after searching on line/ebay for ages without success. I'm using the same gearbox as you.

I also tried to get the gearbox crossmember turrets, but he said that these days they recommend people weld a steel plate across the existing mounts/turrets. Saves having to grind the old ones off.

First I have heard of it - does anyone have any idea how this might work? I can't picture it.


Graham - I tried to find part numbers for you but nothing on Clive's site nor on the web-site for the Canadian distributor for Clive's parts.

Liam - I don't know what they're talking about either. I used the new brackets on the MGB x-member and they bolt up very well. Maybe I'm missing something but wouldn't welding a plate across the existing brackets force the gearbox to sit higher? With space at a premium under the tunnel, I wouldn't want to lose any room.
Simon Austin

Maybe they mean welding two plates, each flat to the existing mounts so that you can attach the new cotton real mounts a little off centre, and not have to relocate the gearbox crossmember.

Hmmm.....maybe but with my cross-member, I didn't have to relocate it. It bolted right into the original MGB frame rail captive nuts. Pleasantly surprised I might add as I had no idea where the x-member would end up.
Simon Austin

Maybe welding a flat plate/spacer to the turret on one side would push the box to one side by the required 14mm or so, but would it not push the box up as well - thereby requiring xmember-to-floorpan spacers to lower it?

On the other hand would it not be possible to just redrill the mounting holes on the xmember itself to move the whole thing over, rather than trying to relocate the captive nuts under the floor. Although, perhaps it would work on one side but you might run out of xmember on the other.

My floor is lovely and new I dont really want to start cutting into it or drilling through it.

Cant fathom this at all. I today finally gave in and bought some new turrets from V8 conversions - who were very helpful indeed.

My honesty in this case lies more in the breach than the observance.

I believe the cotton reel mounts are part number CRC454A

All I can tell you guys is with the new brackets welded in place of the removed original MGB units, the new rubber mounts and the Clive Wheatley engine mounts installed in a RB car, the engine/gearbox will mount into the car without any modifications to the car at all (other than the aforementioned tunnel extension).

This install will give you about an inch of clearance between the left side cylinder head and the car bulkhead (maybe the same or slightly more on the right side).

I can take some pics if anyone is interested.
Simon Austin

I'm hoping that will now be the case for me Simon.

I'll keep you posted.

Do you have any idea what the mounting bolt specs are?

Which mounting bolt specs do you mean?
Simon Austin

Sorry Simon, I meant the ones which bolt up into the captive nuts - I will have to grind the heads off my donor ones and leave them in place to release the x-member.

I can buy them new from MOSS but have loads lying around and would rather waste not want not.

Wouldn't mind a few photo's.

GLG Lavis (Graham)

No problem, Liam. I'll take a look at one of mine and let you know.

I'll send you some pics Graham.

Simon Austin


Bolts are 3/8" x 24NF; 1" threaded shank; 9/16" head.

Simon Austin

This thread was discussed between 08/03/2006 and 14/03/2006

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