Swapping a 7 1/4 for an 8 1/4 does not require and modification to the drive shaft, does it?

I took a tape to both housings and came up with some very close numbers; but I definitely don't want to have the project get ham-stringed by something silly like that...

is the U-Joint used?

Thank you all so much.

Seth

http://www.moparts.com/Tech/Archive/axle/5.html

Needs to be 1.6" shorter. There were only 2 u joint sizes and I'm pretty sure the bigger one was only used on the bigger rear ends. The cup sizes were significantly different (Over 1/8"?) so if you measure you will be able to tell.

that's a great web-page! thank you! -i'm going to climb under my car at lunch to see if the slip yoke at the front of the shaft will be able to soak up the extra length...