Need to swap out my stock rear end

[Sinister G]

First just wanted to say I'm new here. Long time g-body and muscle car enthusiast.

I have a 1986 Cutlass Supreme right now. It has a Chevy 383 stroker in it, extensive cam and head work, etc. It makes about 500hp on paper. It's a 3 speed 350 Turbo Trans. Now the bad part, it's still running the old stock rear end. I don't know the exact specs of the rear end for an 86 Cutlass, but I know it's junk. I'm probably only getting like less than 300hp to the ground because of it. Plus not having posi really sucks. One tire fires all day lol. I wanna throw some fatter tires on the back but I know I'll probably shatter that rear end if I do. I'm surprised it's held up this long.

I found a complete rear out of a Grand National on craigslist for $300. It's posi with a 3.73 gear. It seems like a good deal. My question is how hard is a rear end swap on this year cutlass? Would that rear end be a good one to get? If not why and what's a good one? The Cutlass doesn't use leaf springs which is kinda a weird thing (at least for me and the cars I'm used to working on).

Any help and advice would be greatly appreciated.

 

[GhettoRacingKid]

wow $300 complete.

grab it and grab it now.

the only thing you will need to do is get a shorter drive shaft. its 1 inch shorter. ask the seller if they have it. make sure its an 8.5

they are easy to swap out.

brakelines, emer brake cable, and 8 bolts and your done.

 

[Longroof79]

It's a direct bolt up except for shortening the driveshaft 1" like Ghetto racing kid said. For $300. you'd better grab it.
That's a great deal. I've seen open 8.5's going for more than that. Just make sure he's not trying to sell you another 7.5.

 

[pontiacgp]

It's a direct bolt up except for shortening the driveshaft 1" like Ghetto racing kid said. For $300. you'd better grab it.
That's a great deal. I've seen open 8.5's going for more than that. Just make sure he's not trying to sell you another 7.5.

x2...that seems way too cheap. I'd remove the cover even if it is an 8.5 to see what's inside

 

[GhettoRacingKid]

where are you located? if you dont want it ill take it.

i just sold a housing of an 8.5 for $400

the 8.5 has squared off tabs at the bottom of the housing. the 7.5 has what i like to say are fangs.

 

[Sinister G]

The rear end turned out to be the 7.5 unfortunately.

I guess I'll be on the search for an 8.5
Anyone know a place that sells them new or used?

 

[CHRIS.O]

How deep is your wallet? Moser sells complete bolt in 8.5 rear ends, brand new.

 

[88hurstolds]

If your running that kind of HP go with a Ford 9", it's the most economical way to go.
You can get a housing with Axels for $400-$550 and a pumkin for around $600??? not sure, but I know by the time you get an 8.5" rear used ($900 with posi) and then go and rebuild it (another $400-$500) you can just go and buy a heafty built up 9" for $1300-$1500.
Most people just slap in a sloppy used 8.5" with a sh*t load of miles on it and call it a day
That's all fine and dandy if you're just driving it or using it for a little weekend warrior but if that's the case you can just build up your 7.5" for just around $500. I'm running a 400hp Olds 455 with over 500 ft-lbs of torque in front of a 3.08 posi 7.5" and have never had one problem and I drive the piss out of it...
If your serious about hiting the track a Ford 9" is the way to go, there are tons of IDIOTS out there that just part out perfectly restorable 442's, Hurst's, GN's and Turbo Regals just for some MYTHICAL rear end that is a waste of money IMO.

As they say DO IT RIGHT OR DO IT TWICE

 

[deathproof]

My question is how hard is a rear end swap on this year cutlass?

Any help and advice would be greatly appreciated.

If you've got a floor jack, a ratchet set, a B.F.Hammer, and an extra set of muscles its easy.
😀

 

[Chris Van]

If you run across the right deal on an 8.5 you won't regret using it and it will be fine for street/strip duty. Do yourself a favor and don't waste a dime of your hard earned money on that 7.5
But if you are serious about track time, go for the 9" ford. You can spend as much or as little as you want when building a 9" You can peice together parts and get yourself a pretty good rear end together on a tight budget or you can go all out and wind up with about $3-4000 in it too. (ask me how I know....LOL)
Depending on where you are located and if you did find a deal on an 8.5 I have a driveshaft for one that I'd be willing to part with but I don't want to fool with shipping it.