Thanks for confirmation. I wasn’t sure on a small block gs if they used the 3r. I’m going with 1350 yoke on my 10 bolt build up, I know I can purchase a 3r 1350 conversion u joint. Thanks again.
All Buick Olds and Pontiac used the M3R joint all the way back to 1957 at least... I do noit go back any further than that...lol It is most used GM u-joint... most known now as a 1/2 pick truck u joint. 1 1/8" caps square retaining clips are on the outside diameter grooved cpas that are locked insides of the yoke saddles and drive shaft loops. Jim J D Race
Jim - thanks. Got all my parts for the 10 bolt build up. Just need some warmer weather, will pull the rear out of the gs, get at it.