Disc brake conversion on 1986

Alimony · Posted: Sun Aug 03, 2008 9:42 pm Post subject: Disc brake conversion on 1986

I want to do a conversion to disc brakes on my 86. Also I want to keep the Torque Thrust 15" wheels. Has anybody done this either with a stock rear end or a replacement (12 bolt - 9" - etc.) who can give me some ideas about clearance between the caliper assy and the inside of the rim? Also, any advice about the choice of rearends would be helpful. It seems like most of my friends recommned the 9" Ford but I just hate to go there when a 12 bolt might be just fine. Engine is around 450HP so I think either of them would work and I want to order it with the brakes already installed.

Thanks in advance.
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Bob
1986 El Camino ZZ430 TKO500
2008 Corvette Conv 6 spd w/ZO6 exhaust

1BadElky · Posted: Mon Aug 04, 2008 11:03 pm Post subject:

here is a thread I made on turbobuick comparing all the brakes out there. I went with the PBR kit from Ed Miller, but the LS1 kit would be just as good...

http://www.turbobuick.com/forums/brakes-suspensions-tires-wheels/248262-calling-everyone-rear-discs-those-who-know-about-them.html

I stray away from aftermarket setups because you have to special order the wearparts such as pads and rotors.

if you choose to use a 12 bolt or 9 inch, you have more options. the 12 bolt should have the square axle housing flange so you can bolt up LS1 rear brakes without drilling and tapping like is necessary on our G-body metric flange.

IDK about 9" but I imagine the company will cusom make it for whatever type of brakes you want. If you go to a junkyard to get one, you'll have to use Ford brakes out back. I have no knowlege about them.
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Formerly 86Conquista

Currently undergoing resto.
Planned:
-350/?/3.42
-ZQ8 wheels
-Disc Brakes
-More

Alimony · Posted: Tue Aug 05, 2008 12:11 am Post subject:

Thanks. I read thru that entire thread plus the one that he did with the photos showing his kit parts. My guess is that the 11" disc with caliper assembly will fit inside the 15" wheel. I'm going to take some measurements of it and then get in touch with him. In any event your thread was very helpful and I think probably got me to an appropriate comfort level. Have a nice day.
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Bob
1986 El Camino ZZ430 TKO500
2008 Corvette Conv 6 spd w/ZO6 exhaust

darbysan · Posted: Tue Aug 05, 2008 11:48 am Post subject:

Here are a couple of sites that give info on installing rear disks on a G-body. With your horsepower, you would probably want to use a GM 8.5 if you can find one. Otherwise, the advise above is probably right - Ford 9" being the most popular ( you can find these already modified- just get's a little pricey).

While these may not apply to your situation, they give a pretty good primer on what is needed.

rear disk install
Rear disk install # 2

HTH
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'85 SS, Ash Blue Mica ( 2003 Lexus Color), '87 L69 305, Choo Choo Conversion, Roll Pan, Edelbrock Intake and TES Headers, Acura leather Buckets, 2004 Gp Console and Shifter, 8.5 GN rear with 3.73, GN 200-4r

MEvang · Posted: Tue Aug 05, 2008 8:27 pm Post subject:

Wow amazing how much information some of these article have.
My advice, stay away from the old GM Caddy calipers. They had a load of problems. For one they have to have a park brake and it must be used all the time. If not the self adjusters in the pistons fail, and you start loosing pedal height. They use a residual pressure valve in the one article I guess to try and over come the problems with these calipers, what a bad Idea. Even when they work right you some time have to force the adjusters to work, something us old brake guys learned to do.
The PBR calipers are great, but you loose the parking brake function. Anyone have anything on the S10 factory rear disc brakes?
Mike
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"That the automobile has practically reached the limit of its development is suggested by the fact that during the past year no improvements of a radical nature have been introduced." (Scientific American January 2, 1909).