In my 68 Skylark when I to swap from an 8.2 to an 8.5, will I need a new drive shaft or will my current one be the correct length? And if I do need one, what is the correct length? Thanks
You will need to shorten it around an inch and a half. I don't remember the measurements of the total length off hand
NEVER MAKE THE DRIVE SHAFT BEFORE INSTALLING THE REAR. - GET YOUR REAR END IN AND MEASURE THEN ORDER THE DRIVE SHAFT. This is the ONLY safe way to get the drive shaft the correct length.
Yes, that is what I should of said, I guess I just assumed the OP wanted to know if he could use the 8.2 shaft or not. Measuring is definitely the way to go. Nothing is worse than spending almost $100 cutting and balancing a shaft to find out its too long or too short:laugh:
whenever i did my swap the you had to jack up the car to get the driveshaft in but it fit and would let me roll it around till i got one so i didnt have to chock the wheels. but i wouldnt recommend driving it like that cause it puts pressure on the thrust bearings in the trans.
I wasn't planning on having one made. He has a ton of 71-72 cars and should have the correct drive shaft available if mine is the incorrect length (which it seems to be from what I've found). Thanks for the info though. I just didn't feel like crawling under one in the mud/rain to pull one. I was hoping someone might already have the length of a 71-72 TH350 and 8.5" drive shaft available?
Tim, I had to remove about 3/4" off my drive shaft when going from my OE 8.2 to the 8.5. Of course that was with a THM400 and GV. I think it is very ill advised to do anything but measure, in your car, for the correct one.
The only thing you can do without measuring is use a 71/72 driveshaft from a standard wheelbase A-body, but even then there is no guarantee it will be a perfect fit. I did that and lucked out but I do recall it being a little shorter than I would have liked. This was me going from an 8.5 to an 8.2 though
keep the 8.2 and build it? jim hooked me up with all the good stuff. runs as good as any 8.5 with 3.65 gear jim
Jim, The 8.5 is a stronger rear, and might be cheaper to build depending on how much it costs to get the rear.
+1, its not that you can't build an 8.2, its that it would probably cost the same if not more than an 8.5 and why do that when you can build an 8.5 to be stronger. A BOP 8.5 would be your best bet, bolt in axles sure are nice. I wish I kept my original open 8.5 rear, I will be going back to one once I put a big block in.
Well here's what TA has to say about their 8.2 Buick rear end upgrades: Yes! The Buick engineers did their homework! This is not a typical GM 10 Bolt rear end, but one that was designed for the full size LeSabre and adapted to the `68-`70 GS, Skylark, Special and LeSabre as a durable performance model. This is a well-engineered rear end with strength in mind when designed! This rear end has been overlooked for years due to limited production of performance gears. Now Available in 3.42 and 3.64 ratios making the Buick Rear End a contender for your performance needs. Enormous performance gains can be achieved with just a simple gear ratio change. You will not get full potential from a performance engine or transmission unless you complete the package! Replace those lame “cross country” gears with something that has teeth! Made from USA forgings the 8620 steel ring gear has been held to the most rigid specifications. The pinion is made from 8620 billet bar stock and both heat-treated and finish ground to specifications to + or - .0002. That is 10 times thinner than a human hair. Each and every gear set is lapped to its mating gear, with all set-up information etched into the gears with each gear set serial numbered. Do not confused the standard GM 8.2 gear with the robust Buick 8.2 ring and pinion. Buick did their homework. While this is an 8.2 ring gear as is the Chevy and Pontiac, this is where the similarities end. This is an overlooked, dependable rear axle assembly that should be revisited as a rear end of choice. The 8.2 Buick is FAR SUPERIOR to many of its rivals in so many ways including: Buick 8.2 uses 10 7/16” ring gear bolts (same as Ford 9”) Buick 8.2 uses larger 27 spline pinion yoke as opposed to 25 spline Chevy 8.2 Buick 8.2 uses a massive 1.875 pinion bearing for rigidity that dwarfs the Ford 9” (same as Dana 60) Buick 8.2 uses an oversize bearing and cap on the ring gear side of posi unit for strength Buick 8.2 uses the Mechanics 3R U-joint for reliability Buick 8.2 uses a much lower pinion center line (hypoid) in relationship to the ring gear providing much more tooth contact area as does the Ford 9” Buick 8.2 uses axles retained WITHOUT using the dreadful “C” clip. All Chevy 10 and 12 bolt rear end use this “C” clip system and many quarter panels have been destroyed from this poor design. ___________________________________________________________ Here's the link: http://www.taperformance.com/products.asp?cat=459
All true Gary, but the 8.5 is even stronger. Everything for the 68-70 Buick 8.2 will be more expensive. At one point, you couldn't get a new Posi for that rear, but Monzaz has a way to make one fit.
