I had a similar u-joint issue with my 1967 Firebird. Found that the pinion side actually accepts a 1 1/8" cup. The correct u-joint is a GM 3-RL (S44) style with 1 1/8" caps and inside snap rings on both sides. Spicer part numbers are below:
5-795X (lifetime)
5-3147X (greaseable)
|