Balanced Driveshafts?

[fordman3]

Hey all,
I'm about to swap rear axles from one car to another. I've always been told that we have 'balanced' driveshafts and that if they are not re-mounted exactly as the factory installed them, you will get vibration. Well, when you are mating up a driveshaft and a rear end that didn't originally go together, how are you supposed to do that? Or is that all a bunch of stuff? Do I need to plan to install the matching driveshaft from the donor car as well as its rear axle? Thanks for any advice.

Fordman3

[slicksport88]

I just recently swapped out my 7.5 rear for a 8.8 and have had no vibration problems with the original driveshaft. I was concerned like yourself but so far so good.

[Chuck W]

It's always "best" to keep them installed the way they came off the car, but "usually" it makes no difference. Install it and drive it...you'll know once you get the car up to speed if you're going to have any issues or not.