need help identifying these rear ends. from other threads i have determined that they are ten bolt 8.5s 1 has 342 gears w/posi and a 5X4 3/4 bolt pattern the other has 308 gears w/posi and a 5X5 bolt pattern, they both seem to measure roughly 55 1/2 wide from backing plate to backing plate. the shock mounts are on the front side of the axel tubes. as you can see from the pics. they are not from skylark, any ideas?. also would the carriers and gears fit in a 8.5 skylark houseing or would they be different?? thanks
would these fit in an 8.5 chevy houseing if i used c clip illiminators?? is pontiac an olds the same as buick? or would i be better off selling these and buying aftermarket 8.2 posi, ring and pinion?
For GM A-bodies....Chevy didn't use an 8.5......only Cutlass and Skylark had the 8.5.....so you will need one of them in order to use the 8.5" posi unit and gears. Best solution...get an 8.5" from a 71-2 Cutlass/Skylark
i may have found a 71 cutlass rear end. will these units i have be a direct bolt in? will my backing plates, brakes, drums, and drive shaft u joints fit? any mods ill have to do? are the olds axles bolt in or are they C clips? thanks for your help
ok i got a houseing from a 71 cutlass. the rear was removed so i had to take his word for it. im hoping i didnt screw up. here is som pics of it please tell me i got the right one. the numbers on the ring gear are 41A16 GM TU 86 2
That is a Chevy rear axle.....see the article below to correctly identify the Cutlass/Skylark 8.5" rear axle.....u just got an 8.2" http://www.buickperformance.com/85rear.htm
not according to this thread and monzaz. please read and let me know thanks http://www.v8buick.com/showthread.php?t=170040&highlight=8.5+posi
I read it....all the 8.5 Cutlass/Skylark rears I have seen have 2 plug welds on each side of the center section to hold the axle tubes in and there are 2 cutouts at 9 and 3 o'clock positions. Did you verify if the rear has 2 straps and 4 screws to hold the rear u-joint in place??? Here is a pic of the 2 plug welds.
yep its an an 8.5 out of a 71 olds cutlass, put the posi with the 342s in yesterday, perfect match. a little more cleaning and some paint and its ready to put in the buick. cant wait to see what the difference will be from the original 290s. now i have an extra 8.5 posi w/308s and a 8.5 open w/256s gears. :3gears: any interest out there for these? what are they worth? thanks again for the help guys:TU:
That is a 8.5 Olds rear. They will BE the only rear that does NOT follow the 5 and 7 o'clock triangular casting. They are VERY easy to get mixed up with Chevy rears. They are very hard to ID with out a trained eye. If you are diligent in going through the ID steps you can still find them out there. DO NOT GET HUNG UP ON THE REAR COVER DEAL AS IT WILL THROW YOU ON THIS PARTICULAR REAR ALSO. You will be fine all the guts from the other 73-77 rear will fit right into that housing. Good luck and glad the site helped you get a rear under your car. Jim
LOL...73-77 a-body regal, elcamino, monte carlo cutlass, grand prix... IF they have 4 3/4" on 5 lug bolt pattern If the bolt pattern is 5 x 5" bolt pattern it is full size 1978-1996 impala, lesabre, buick full size...NOT WAGONS!! 1971-1977 full size were a tad bit wider in the lower control arm mounting and the spring perch area and of course the shock mount. and over all width. 88 98 wagons royale... That is it
