MG Sports Cars

I found a rusty TR8 with a good drive train, and I'm thinking about putting the engine and transmission in my MGB GT.

Can the TR8 rear end be used in this swap to get a rear end that will handle the power? I know I would have to adapt the MGB springs, but I'm wondering about the axle width, wheel bolt pattern, axle ratio, etc. and whether they would be a good match.

Dale, I don't know about the axle width, but the tr8 had 13" wheels and I think a smaller pcd on the bolt pattern...also it did not have leaf springs, but rather a coil spring setup with telescopic shocks and radius rods...much more sophisticated than the mgb...the tr8 engine only generated 137 hp so the mgb rear axle in its normal state is more than capable of handing the tr8 power...on a postitive note, the tr8 rear axle ratio was 3.08 and made the car a very relaxed cruiser...it would be a ton of work to convert the tr8 axle to an mgb...if you wanted the better ratio, you could install the mgc gearset into your mgb axle from someone like clive wheatly...with a lot less aggravation...

I agree with Mike. You won't have any problems with a B rear axle. I'm using a stock unit in my 3.5-powered roadster and that engine is putting out about 175hp and 190 ft/lbs of torque. The engine came from an '80 Rover SD1.

I did install the 3.07 gears from an MGC so that helps.

Dale,

I would stay away from the TR8 rear end if you plan on having an upgraded suspension; bushings, springs, sway bar, etc. It is rare for a TR8/TR7 tube axle to be vibration free when the suspension no longer has stock bushings and you reach 200 hp. The rears tend to develope axle whind for the outer bearing, excessive lash in the pinion gears and the drive shaft flange also wears and adds to the whole mess. The other issue is the real small drum brakes and a 95.25mm bolt pattern that limits rim selection. Considering all that to cutting and welding to adapt for leaf springs and shortening, when it would be all said and done I would have save time and upgrade the MGB 3.90:1 ratio rear to a MGC 3.07:1 ratio with a LSD or go for it all with a Ford 8.8 or Dana 44 with a LSD.

Michael