This year didn't come with a super t10. I suspect the driveshaft I'm using is giving me a driveline vibration. Perhaps it isn't balanced correctly. I want to get a new yoke for my original 350 auto trans driveshaft and try it to see if it solves the issue. Super t10 is from a 76 firebird. Do I order a yoke for a firebird? The rear end in it now is out of an 81 camaro. Are the u joints larger than the 76 rear end?
Don't fire the parts cannon and pray. Wobble the yoke in the trans. tail. If it visibly moves, you need a bushing at a minimum. Because the material of a bushing is sacrificial, yokes can often be just fine. Remove and inspect. The common u-joints in GM cars near the era were 1310 (outer retaining clips) and 1330 and 1350 (common upgrade people aspire to,) plus lots of 3R (inboard retaining rings.) If you google those sizes, and measure yours, you'll be able to answer the question of what's in your car and order correctly. Don't rule out conversion joints which can match a (13x0 or 3R) yoke to a (13x0 or 3R) driveline.
The driveshaft that I'm using was brand new when I bought the trans from a local guy. I was thinking it may have been out of balance but your correct, I'm really not sure this is my issue. I just figured if I could get a new yoke for my original one I could rule that out
GM switched to the 3R U joints in '76. This is what the '81 rear end will use. The '76 drive shaft should have 3R joints, but check it to be sure. The ST10 has a 32 spline main shaft and the TH350 has a 27 spline shaft. You will need a 32 spline yoke for the ST10. I've got a drive shaft for sale from a ST10 car, but the yoke is damaged.