Going to spend my vacation the next week pulling out my factory rear end, and putting in a posi-rear out of a grand national. Any tip, tricks, or suggestions that would make this easier. Never done it before, so it will be a learning experience for me. Just ordered the gasket, lube oil, and additive from gmpartsdirect so that is covered. What I am concerned about are seized up bolts, and just what other troubles that might arise unexpectedly. My regal is a 1981, and the rear has never been removed.(Atleast not since I bought it in 1991) I will have to convert my brakes over, since the rear I bought has nothing except for the little brake cylinders. I guess the brake components will swap over???
The bolts for the lower control arms will almost certainly be frozen to the bushing. Make sure you can rotate your wrenches by at least 180* to break the little suckers loose as an airgun will just cause vibration.
Backing plate bolts like to snap. Also, you do know you need a GN driveshaft as well...right? 8.5 rears have a longer snout, thus needing a shorter shaft than the one for a 7.5.
Was wondering about the drive shaft. Have had some people tell me it will be the same, some people tell me I will need a GN driveshaft. So I won't know what to expect until I get it out. Started on it today. Some of the bolts came out easily(lower), while some are pretty darn snug(upper). Soaked the tight ones in WD40 before I left so hopefully tomorrow I can drop it out.
The 8.5" rear is 1.1" longer than the 7.5. Unles you're moving the engine/tranny you'll need a new shaft. Not a bad idea to upgrade to a thicker wall though, they're usually less than $200. Beats pole-vaulting your car over the track...
Check the yellow pages for a driveshaft rebuilder. It's a very common service. Having your original cut, welded and balanced will work fine, but as long as you're doing all that work, a few extra $$ for a new thicker wall tube is a pretty good safety investment. Your old shaft has 20+ years in it and is about to take a LOT of torque. Stock GN driveshafts have been known to twist up pretty well too...