[ta man]

Originally Posted by 78w72

thanks for measuring it. so it looks like about 1/8" for the pinion yoke & 1/16 for the Ujoint, 3/16 total difference using the 1350, shouldnt be an issue if the shaft length can compensate for that.

can anyone confirm what rear joint a 72 firebird with 350/350 used? i will measure to confirm before i order but i always thought it was a 1310 that uses the straps to hold it in the diff yoke that has centering tabs. did they change to a smaller u joint for later years, is that maybe the 3R?

It should be 1/4 inch for the pinion yoke. Zero for the u joint swap from a conversion to 1350..the u joint is measured from center..the center on the driveshaft u joint does not change when its swapped from a conversion u joint to a 1350. Your total driveshaft length required becomes 1/4 inch shorter.