I went from an 8.2" to a 12 bolt.... are the drive shafts the same length ?

On a "quick trip" down the road I found I have a vibration I didn't have before. The witness marks on the slip joint are out about 1" more (1" more shiny metal showing)

I don't think the driveshaft length is different...beware that your rear is positioned properly on the springs, an do not forget to "re-torque" the ubolts...

Backing out of my driveway some years ago (a steep hill) after swapping a rear, the rear "broke loose" and slid on the spring back just enough to tear the driver's sid 1/4 panel up!

I am finishing up the exact same swap. I went from a stock 10 bolt to a Moser 12 bolt with 1350 pinion yoke. I was told I would have to shorten the driveshaft but I just sized up my old shaft and it looks like it may fit. I will still need to change out the p/y on the shaft to match the one on the rear but I really don't think I will have to shorten it. The pic below shows the p/y spacing on the rear/shaft while the driveshaft is fully inserted into the transmission.

http://www.mattlekawa.com/pictures/camaro/driveShaftPinYoke01.jpg

http://www.mattlekawa.com/pictures/camaro/driveShaftPinYoke02.jpg

I swapped mine several yrs ago and am still using the same driveshaft, And I saw only minimal wear mark locations differences on the yoke.

OK, sounds like it good. Thanks