Rear end swapping

[LukeZ]

hey guys, one quick question.

I have an 86 SS El Camino that is all stock with the 305 V8, a 200R4 overdrive transmission, and a 7.5" 2.56:1 rear end, with the drum brakes and all in the back too. Like I said, all stock. I've been wanting to move up to a 8.5" rear end for awhile now, and specifically I want 3.42s. Now I know absolutely nothing about rears, so I'm just wondering: could I just buy the gears, posi, and gear housing from a website, and get a shop to install them for me, keeping me axle and brakes, or is it not that simple? To be honest, I just want to know what I need to buy for a shop to swap my gears, and if I need a whole new axle. If I do, does anyone know where I can get what I'm looking for for a deal? And i doubt junkyards will have exactly what I want, so I probably won't check there. Thanks.

 

[wonderboy24]

i did the same. bought a 8.5. had 3.73 posi unit installed and new gears. kept the same axles. cost 700.00 for the posi unit and gears bearing ect. was charge 300.00 labor to install every thing.

 

[theoldsone]

Nothing from the 7.5 is really the same as the 8.5. If your starting with a bare 8.5 case You need new axles/carrier with posi/ring and pinion/carrier bearings & race/pinion bearing & race/axle seals/axle bearing/aluminum cover. That's how I would do it at least. And if your not going to do it your self then get ready to put down some $$$ to get all those parts installed.

 

[84_SS]

Depending on how much money you are looking to spend you can get a pretty nice made to order rear end for around 3500-4000$ I did a moser m9 fabricated 9" rear end for my car, love the way it looks and it literally dropped in the car no hassle.

 

[HAFROD]

If your keeping the stock 7.5 and putting in the good stuff, I'd recommend this. It has bearing cap supports http://rover.ebay.com/rover/1/711-5...0001&campid=5335822911&icep_item=191408455541

 

[pontiacgp]

A relatively cheap upgrade is an 8.2 from a 64 to 67 Chevelle. I'll handle up to 500 hp and it's a bolt in with conversion control arms. It's 2.5" wider then the G body rear so it adds stability to the car and it has bolt in wheel cylinders so it improves the rear braking. The wheel studs need to be changed to the metric and it uses the same brake drum you have on the G body. I bought mine for $600 with a 3.08 Eaton posi. The only thing I had to do was replace the two thust washers on the pinion gears. GM had a service bulletin on them, the material they used was too soft and wore down prematurely. The ones I took out were paper thin.

 

[JBreu]

Or get a 12 bolt rear from a 64-72 a body cars, not the olds 12 bolt though. Like pontiacgp said, all ya really need it to get the 12 bolt swap kit from umi...Will be the last rear you ever buy.

 

[TexasT]

Unless you have an 8.5 ten bolt located and ready to go, I would suggest moving to a 9". The search, shipping, parts and labor you get pretty close to one of these that comes ready to bolt in.

http://www.quickperformance.com/9-Ford-Complete-Rearend-GM-G-Body-78-87_p_20384.html

Check the boxes, give em your card number and bolt it in. Then you can punish it pretty much any way you wish. Ready for any and all future upgrades.

That said I am using an 8.5 but my car came with it. If it ever breaks you can be sure one of these would be on its way to my house.