Rear disc conversion... Need help!

[loucks10]

I have a '52 Chevy 1/2 ton.. mixed and matched all over, semi-custom. '73 Nova front clip with discs (7/16" stud on 5x4.75" bolt pattern). The rear end is a GM 8.875" 12 bolt out of a '73 truck (1/2" studs with axles redrilled to 5x4.75" bold pattern). I want to get discs on the rear but with 7/16" studs on 4.75" centers.

My question is will the GM 12 bolt "car style" disc brake kits fit onto the 12 bolt truck housing? I'm completely ignorant when it comes to rear ends, so does anyone have some insight? If the car kit works, then I can pass on having the rotors machined to 4.75" centers and pressed for 7/16" studs, instead of what they come with (5 on 5" with 1/2" studs). I don't know if the plates on where the kits hook up are the same housing size? Or if the axle size would be different and not fit into the hub? Any advice would be greatly appreciated. Thanks!

[mr48chev]

It's going to take some measuring and trial fitting but It shouldn't be extremely difficult

Probably the best rotor choice would be http://www.oreillyauto.com/site/c/de...0062&ppt=C0009

That fits a 79/81 Pontiac Trans Am and should be readily available.

You might be able to modify a pair of Trans Am caliper brackets to work on the truck axle. Or there are caliper brackets for putting disk brakes on 4x4 rear axles that might work with some modifications. I picked up a pair of bolt on brackets from this vendor for my 3/4 ton GMC and they did a really nice job on them. These are weld on but they could be modified or they could give you some idea of how to fab your own out of 3/8 plate. http://www.ebay.com/itm/Chevy-12-Bol...item3ca9fee4a9

[loucks10]

So far the issue I have now ran into is that the axle plate is 6 5/8" diameter, making a car style rotor unable to fit over it. It has 5 x 4.75 bolt patern on it. Is there a rotor with that bolt pattern that will fit over the plate, or do I need to get the axle plates machined down to 6 1/8" to work with a disc setup? Trying to figure out the most cost effective, but universal way... to get discs on the rear and have the same bolt pattern as the front.

[loucks10]

Here is the kit I think I will run... Only machine work that will (hopefully) have to be done is drilling the rotors to a 5x4.75" bolt pattern.
http://www.jegs.com/i/Right-Stuff/965/TRD4705/10002/-1

[sweet70beast]

I put rear discs from a 79 Cadillac and a 79 Firebird on my 70 Nova. The backing plates and calipers are from the Caddy and the rotors are from the Firebird. I had to have the axle flanges turned down to fit in the hat of the rotor. The Firebird has the 5 on 4 3/4 bolt pattern and the Caddy has a 5 on 5 pattern but the rotors are identical. In fact I re drilled the Caddy rotors to fit my axle until I found out the Firebird rotors were the same.
I wouldn't be surprised if the Caddy set up fits right on to your truck 12 bolt. I think it was a 79 Cadillac Seville that I got the rear brakes off of. This works great for me because I can get factory parts from any parts store anywhere.