Hey guys, I'm currently doing a 350 swap in my xj6 series 3. And I was wondering if I'll have to change the drive shaft and/or the rear axle. I've been searching forums and websites to try to find the information I need but can't seem to find it. So I was wondering if someone could help me with their knowledge. Thanks in advance.

BigNorm

 

If you keep the stock 2-piece drive shaft, my preference, the front shaft will more than likely need to be shortened or lengthened. It will depend on where the engine gets positioned and the length of the transmission you use. You will have to mount the engine/trans in place before an accurate measurement can be done. In any case, the front drive shaft yoke will need to be changed to match the output shaft of the transmission. The IRS doesn't need any change of position.

Dave

 

Thanks a lot. Do you think the differential will be able to handle it?

 

The diff itself is very robust. I’ll toss out a number and say it’s safe for 400hp. Opinions may vary on that.

The rubber mountings for the rear subframe will be the weak spot if you have a hot V8. Should be Ok for mild versions…..assuming they’re in good shape to begin with.

Cheers
DD

 

Apparently the diff itself is good for numbers approaching 600hp. Jaguar was getting some very large power outputs from their experimental 4 valve 6.4 V12 and the standard rear suspension was fine.

The rear end will be fine with anything a 350 can throw at it.

 

It's virtually identical to the rear differentials in 1/2 ton pickups of 30 years ago as well as the front differentials of 3/4 ton pickups (Dana 44). As said, plenty stout unless you are the type that can demolish an anvil with a rubber hammer. As Doug has advised, the 4 rubber sub-frame mounts will be the weak point if you're going to thrash it.

Dave

 

Perfect, thanks for all the responses guys. Really appreciated.

BigNorm