Quote:
Originally Posted by ponchonlefty
just curious why would you change the yoke? the reason i ask is i have a 72 catalina.
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'65-70 P series big Pontiacs took a different pinion flange than comparable '71-76 Big Pontiac's. though they will fit on 12 bolt Chevy pinion (& seal), they are not something I use on 12 bolt builds, by using one, one creates another issue, driveshaft yoke compatibility.
GM oruginally built c-clip 12 bolt rears with 3 different pinion flanges (yokes):
-Most common was the style that accepted the small Chevy ujoint (Spicer1310)
-Next version accepts the larger spicer 1330 ujoint. Have only pulled these from rears original to '70 & 71 12 bolts from higher perf Chevelles & Elco's. They may have been used in '69 as well. The ones I've reinstalled used straps & 7/16 headed bolts.
Both the 1310 & 1330 flanges had small **** towards the outside of the pinion flange to locate the external clip type ujoint caps.
-last is the 12 bolt 3R version. The 3R is very similar dimensionally to the Spicer 1330 version, but a 3R ujoint uses internal clips, so flange is smooth to the end of the bore. The oem 3R pinion flanges for 12 bolts are not that easy to come up with used, & the average knowledge mechanic can easily damage the flange where the u-bolts go through. During 12 bolt builds with factory 3R 12 bolt pinion flanges I always set pinion depth without a crush sleeve & use a common 1310 pinion flange. Once pinion depth & backlash are exactly where I need, I disassemble & carefully reassemble with the 3R pinion flange.