Not a huge rush at all but I am giving myself options for my car. Started life as a 1972 so it has a peg leg 8.5 in it . I secured a 1970 8.2 3:64 rear (not installed) years ago so I am “thinking” in keeping with converting all 72 parts to 70 that the correct 70 driveshaft will be an easier install then any issues with the 72 driveshaft mating up to a 1970. Thoughts are appreciated if I am in error on that. I still also have a 72 8.5 3:42 (needs rebuilt) that would be a plug and play if I give up on “all 70 parts” on my car but I really do not want to invest the money on a rebuild on this money pit. Thank you for thoughts,suggestions or options.
The 8.5" factory rear in you car or the spare 3.42 are stronger than the earlier 8.2" rear. I would put the effort into keeping the "larger" rear in the car. I speak from years of experience with these rears.
Wouldn't a '70 Skylark 350/auto DS be the same? I'll have to check the lengths but that's what I have for my '70 GS 350 4-sp and I thought 455 4-sp was the same length. The one I pulled from one of my parts cars was a 1 pc.
The one I pulled out of a '70 Skylark/Auto is one piece. I guess poss it wasn't orig. or the wrong one was installed orig. but car seems pretty orig.
The 4-speed driveshaft and the TH350 share same shaft as well as the same yoke I believe, 1968 through 1972 A bodies. ***edit*** I should explain, with Buick only. the other A bodies like Chevelle's with the "rock-crusher" M-22? use the same as the TH400
That's what I thought - 4-sp. (350 & 455) were the same as TH350. Mystery is the one-piece I pulled from a Skylark/auto (Flint car). I have 2 more '70 Skylarks here (both Freemont).
Ah... gotcha. makes sense. Us people in the parts world consider a 2 piece drive shaft, being a shaft that uses a slip joint to connect the two shafts. With almost always divided by a carrier bearing. That shaft you showed me is basically glued together and not "designed" to come apart.
Hmm... and never noticed the two shafts (4-speed vs TH350) were built in a different way even though they would interchange in use. Learned something today!!!
Yes,the TH350 and small-output 4-speed use the same length driveshaft and yoke. The TH400 and the large-output 4-speed use the same length driveshaft and yoke. The BOP 8.2” rears use a shaft that is 3/4” longer than a car with an 8.5” 10-bolt. Hope this all helps.
Just went through this as well the 70 driveshaft for my 70 GS 455 4spd is a one-piece shaft that is 56" from the center of each ujoint cap.
I’m possibly in the market for the same unit and coming up with an unstamped part #7804819 for 3&4 speed manual and 7806236,7806237, and 7804858 for A/T. Just out of curiosity I stopped by my friends extremely original’70 judge R/A III, 4spd.
The car in my avatar was originally a 1970 W-31/T-350 car; came with a 2-piece driveshaft. We actually used the 2-piece shaft for a while, when we first started running it in F/SA, with slicks and it held up to wheel stands and low 12 sec. ETs.
