C4 brake questions

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Feb 23, 2007 | 01:59 PM

whitess

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From: Frederick CO

C4 brake questions

I asked these questions sometime back but I couldn't find it so I hope y'all will bear with me. This is for a non Corvette project.

My questions are about the C4 non-HD brake systems (JL9?).
84-87 & 88-94: What size are the rotors (diameter and thickness) and are the calipers single or dual pistons?
Thanks so mich for any help!
Larry.

Feb 23, 2007 | 02:13 PM

GKK

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From: Northern California

The front non HD rotors are 11.5" in diameter and .80" thick. The 84-87 front calipers are single piston and the 88-94 calipers are dual piston.

Feb 23, 2007 | 04:32 PM

whitess

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From: Frederick CO

Thanks a lot for the help. One more question, did any C4's ever come with 12" or 12.25" rotors?

Feb 23, 2007 | 05:42 PM

GKK

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GM and the aftermarket refers to the 11.5" rotors as 12". J55 is the RPO code for the optional front HD 13" rotors standard equipment on the 95-96 C4 Vettes.

Feb 23, 2007 | 11:05 PM

Rabbit1445

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Are they 84-87 front calipers interchangeable with the 88-94 calipers? If so, would there be much of a performance difference?

Feb 24, 2007 | 12:03 AM

GKK

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The 84-87 front brake calipers have a different caliper bracket mounting position than the 88-96 Vettes so, no the 88-96 front brake calipers will not fit.

Feb 24, 2007 | 03:27 AM

wdo-mkr

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The 84 spindles are a one year only part.
85-87s are interchangable with respect to the brakes.
88-96s are interchangable with respect to the brakes.

You might consider just upgrading the brakes on your project to C5 parts. See my offers over in the forsale section. We make the adapters to put C5 brakes on either Model Year grouping.

85-87 Model Years:
http://forums.corvetteforum.com/show....php?t=1626372
88-96 Model Years:
http://forums.corvetteforum.com/show...1611445&page=2

Feb 24, 2007 | 08:37 PM

whitess

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From: Frederick CO

Thanks all. What I'm trying to do is keep the stock 15" aluminum wheels that are on the car now. That's why I'm trying to stay with the "12's". I've got different spindles for the car with a adapter brackets that'll accept the 13" brakes but if I can keep the 15's I'd be happy. The car is an '85 Monte Carlo SS with spindles from an '01 2WD Blazer (same spindle as the Monte but with DP calipers) with 11" rotors and the same hub style as the Corvettes so any of the Corvette C5/6 rotors and calipers will work with the adapter brackets on the Blazer spindles. Maybe someday I'll go with the bigger rotors, wheels, etc. but for now I'd like to stay with nothing more than a 12" and have an adapter bracket made.
Thanks again for the help.
Larry.

Last edited by whitess; Feb 24, 2007 at 08:40 PM.