rear end?

[wilson]

what size rear end is in a 75 malibu? and will it fit in my 86 gn? my car only has the 7.5 someone snagged it along the line. so i am looking for the next best thing.any other cars you know of with 8.5 that will fit even with a little modifying. i am pretty good with a welder.

[monzaz]

1975 malibu is a 8.5 . The uppers are the widest control arm mounts out there on a GM rear. pretty tough to make them work. 1971 1972 skylark and cutlas rears were 8.5 and will be pretty good to do plus having bolt in axles is nice too. It will require the same mods as a 12 bolt chevy. upper conversion control arms and a bit of spring perch relocating also the shock mounts need some redrilling and or different add on plates to relocate that you can do yurself pretty easy. Hope that helps some. Jim

I am working on a 12 bolt GN rear as we speak. it will be for sale soon. 3.73 posi direct bolt in except for the upper control arms. the conversion arms will probably be sold with this rear as a package deal. Jim

jdrace.com

[turbofish38]

I've got a rear axle from a 72 Skylark under my 86 GN. Same thing as what you are trying to do more or less. Only I think your overall length is way to wide with the 73-77 vintage A-body axle. I bought a kit from HPMotorsports in Omaha NE back around 1996. I couldn't find thier website but pick up a Fast Fords&Mustangs and they'll be in there. The kit was all 4 arms and new spring and shock mounts. You've got to do some cutting and welding. With my combo the axle tubes were 1.5" wider on each side. I made up the difference with some custom made wheels. I found I was able to stuff a 10" wide wheel and keep the rubber stuffed up under the sheet metal. I ended up with a 6.250 back space. I would imagine it would be more with your 75 axle. The kit from HP is to swap older A-body axles into a G-body. The arms are boxed and come with poly bushings.

[PaCemkr86]

Eric lets see a pic of your setup

[turbofish38]

I was interested in a cheaper alternative for a stronger rear end in the G-body so I decided to use the 64-72 A-body axle after one of the local Stock Eliminator guys told be how he stuffed a 65 12 bolt up under his 79 Malibu. The rear I picked is from a 72 Skylark I was using as a nuts and bolt car for my GS455. It is the B-O style that uses a pressed on bearing like a Mopar 8.750 or Ford 8/9". No need for C-clip eliminators as it doesn't use them. I had all of the rust and gunk removed by a local chemical stripper. The housing was soaked for 1 week until it looked like it was brand new. That is it in pic 2 before the spring and shock perches were welded on.Since this axle uses the standard GM 4 bolt flange I used some 11" drum brakes from a 77 ElCamino on it with some light weight drums. Notice the cooling fins aren't that large in pic 1.The stock park brake cables bolt right up with no mods needed.I went with drums becuase they needed to look stock for Solo2.Plus I can powerbrake the car up past 20 pounds if I want to. Pic 4 shows all of the hardware from HP Motorsports.Pic 5 shows the stock sway bar bolted to the box tube lower arm.Pic 3 shows the 72 rear with a stock 8.5 rear. Notice the difference in tube length. To build up the rear I used a boneyard 8.5 posi from a B-body wagon.Cost $25. I used a house brand 3.42 ring and pinion from Summit. Cost $135. The wheels are stock GN chrome steels widened to 10" with a 6.250 BS.Cost $125 each. The HPM swap kit is actually the second set they made. The first was a proto that was used to build the jigs. Since I was buddies with Paul Brown I just paid the cost of materials which was really nothing. Retail of the kit was around $300. A friend of mine welded everything up after I mocked the parts up in my garage.When I drag race the car I use some Weld 15X8 wheels with a 5" BS and a 10" wide slick. I'm using F-body springs cut down to lower the car over the tire combination. Since the roll center is a little off the 60' times are off by about .050-.100 seconds. With the wider rear track it handles like a slot car on rails.

[turbofish38]

Here are some pics of how the rubber looks. When these were taken I was running a 285/40-15 tire on the 10" wide rear wheels. That size is non-existant today so I've been running anything from a 275/60 DR to a 265/50 Dunlap street tire on it. These sizes have a little taller side wall so I've had to raise the rear a little by stuffing another set of F-body springs in it.

[PaCemkr86]

very nice info and pics.. im really diggin how far the wheels tuck under.. looks great !

[Survivor87]

Plus I can powerbrake the car up past 20 pounds if I want to.

Man, that is impressive. I also admire the stance and the wheel spacing you achieved with that set-up. Off subject, but where did you find that power 6 Buick plate that's on the front of the car?

[turbofish38]

Off subject, but where did you find that power 6 Buick plate that's on the front of the car?

Ken Mosher picked up a few of those,must be going on 20 years ago. I think from Dennis Kirban. I see them in the swap meets at the GSCA Nationals and from other Buick venders every now and than.

[kenmosher]

I think I actually found them from some metal sign maker outfit waaaaay back in the old days.

Can't remember, but they are pretty neat, huh?

[monzaz]

I noticed there are 2 different rears in the pictures. 1 and 2 are the 8.5 10 bolt corp rear pics with bolt in axles and the others axle 4 5 6 are 10 bolt Buick 8.2 rear that has a posi tag on the rear cover. The 8.2 rear pics 4 5 6 you can not find gears for so be careful if you are racing it. Once they blow you either have to find used gears...RIGHT or junk it. The 8.5 is the rear you can get all the parts for. Just so people do not get confused.

The 8.2 10 bolt we call it the GS rear 1968-1970 came with a larger driver side carrier bearing(A36 12 bolt carrier bearing) and the pinion shaft inner bearing is 1.875 and tapers down to 27 spline yoke where is where the weak link comes in. It has the same size spline as the 7.5 10 bolt . The 8.5 has 1.625 inner bearing shaft (like a Chevy 12 bolt) and only tapers down to a 30 spline yoke (which is also the same as 12 bolt chevy).

Have fun with the conversions looks good. I do 12 bolt chevy with 7.5 axle tube conversion rears ...they seem to work great. they are exact width and the only thing you need are the upper conversion control arms. Take care all . Jim

J D Race.com

[PaCemkr86]

I think I actually found them from some metal sign maker outfit waaaaay back in the old days.

Can't remember, but they are pretty neat, huh?
yes.. do you have any more??

[kenmosher]

Only on my garage walls :cooldance

[Survivor87]

Yeah, exactly the design I was looking for. Thanks, guys. Sorry for taking the thread off course.

[turbofish38]

I noticed there are 2 different rears in the pictures. 1 and 2 are the 8.5 10 bolt corp rear pics with bolt in axles and the others axle 4 5 6 are 10 bolt Buick 8.2 rear that has a posi tag on the rear cover. The 8.2 rear pics 4 5 6 you can not find gears for so be careful if you are racing it. Once they blow you either have to find used gears...RIGHT or junk it. The 8.5 is the rear you can get all the parts for. Just so people do not get confused.


You are correct. I completely forgot the first axle I ran was the 8.2 out of my 70 GS455. It's the pics with the unpainted gear cover. It was a factory 3.42 so I thought what the heck. A 455 S1 makes 510 lb.ft. of torque so it should handle a mild TR,right? Darn near blew the teeth off the cone clutches and cracked the case. Oh well I'm going to Buick hell for screwing up rare parts like that. :duh: Yep. No parts availabilty. Scrapped it and started over.