75-79 X- Body -[9C1 police handling pkg]- questions

[CadVetteStang]

I’m thinking about another dirt-cheap to build autocross project car. I have the idea of duplicating a 9C1 police Nova handling package for a 75-79 GM X-body and possibly making some additional improvements as well. I read where it would corner with .89 Gs and stop with just over 1 G.

From what I have read, some of the 9C1 pkg was simply stock Z28 Camaro parts – as in: Steering box (– or steering gears in the Nova box), Z28 front sway bar.

Were the brakes from the Impala?
Was it a 5 on 5 or a 5 on 4 ¾ bolt pattern?
Was it a 10 bolt or 12 bolt rear end?
What was the gear ratio?
What were the front springs from?
Does anyone know the complete parts list (and donor vehicles)?
What about front and rear sway bar diameter and spring rates?
Did the shocks have a 50/50 ratio?
Was this pkg available for order on a 2 door model?
What radiator was used in the heavy duty cooling?

Has anyone worked out a better salvage yard swap suspension upgrade for the Nova?

I understand that better balanced components may be available from the aftermarket- but this would be a zero budget salvage yard build. The only thing I would want from the aftermarket would be shocks and bushings.

Who has 50/50 ratio sport shocks for it? ~ KYB Maybe?

I prefer 5 on 4 ¾ bolt pattern, but could live with the 5 on 5 if that is the only way to go 12” or bigger on the brakes. I would be more open to a compatible brake swap than a spindle swap because I do not want to throw the geometry out anymore than it will by lowering the car 1” or 2” Can a C3, C4, or C5 brake setup be swapped onto the Nova spindle?
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[Apogee]

With respect to the front brakes, you can run the late-model GM tall-spindles from the 91-96 B-bodies with 12" rotors (as well as a host of other makes/models through the 80's). Obviously, the B-body rotor is 5x5 however the 1LE F-body rotor (88-92?) is the same as the B-body rotor only with a 5x4.75 pattern. This set up will still allow you to run 15" wheels if that's part of the plan.

C5/C6 Corvette brakes are an excellent big-brake option with the GMTS spindle, however they will require 17" wheels and Corvette parts don't tend to come as cheap as B-body parts in the wrecking yards. C3/C4 would be a waste of time, effort and money in my opinion considering if you're trying to maximize your performance per dollar spent, although they have some merit if you're going stick with a 15" or 16" wheel.

Good luck,
Tobin
KORE3

[CadVetteStang]

Obviously, the B-body rotor is 5x5 however the 1LE F-body rotor (88-92?) is the same as the B-body rotor only with a 5x4.75 pattern. This set up will still allow you to run 15" wheels if that's part of the plan.



Thank you for that information: However, another question: the 1LE F-body rotor (88-92) would require the use of that a high offset spindle because of the 88-92s greater positive offset, right? That would mean more scrub and less fender clearance with a standard offset 15” wheel. However, I could use 16” or 17” F- body wheels on the car with no problem. What spindle would that rotor fit on?

[Apogee]

The 3rd generation F-bodies don't use what I would call a "high-offset" spindle or wheel, hence the need to run wheel adapters when running high-offset wheels on such applications. You may be thinking of the 4th generation (1993-2002) F-body applications.

IIRC, the 1LE rotor has the same track width per side relative to the inner wheel bearing than the smaller 11" brakes used on your factory Nova setup. The 1LE rotors will require a SET3 outer wheel bearing, so only the .844 diameter spindles will be compatible if you decide to go that route.

Tobin
KORE3

[CadVetteStang]

You may be thinking of the 4th generation (1993-2002) F-body applications.

Yes, I was thinking of 4th gen - oops :D


The 1LE rotors will require a SET3 outer wheel bearing, so only the .844 diameter spindles will be compatible if you decide to go that route.

.844 diamiter spindles? So are the B-Body spindles .844 diameter? If that is what you meant, then they would be a direct swap to B-body spindles without thickness issues or caliper bracket spacers - right?
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[Apogee]

.844 diamiter spindles? So are the B-Body spindles .844 diameter? If that is what you meant, then they would be a direct swap to B-body spindles without thickness issues or caliper bracket spacers - right?

The 91-96 B-body spindles use SET6 inner (1.250" ID) and SET3 outer (.844" ID) wheel bearings. There are two versions of the B-body spindle with respect to the lower ball-joint size, with the smaller one being 9/16" and compatible with the 75+ X-body control arms. The 5/8" lower ball-joint spindle found on the 9C1 Caprice and wagon applications is the same casting and spindle pin, it just has the lower ball-joint hole machined for the larger ball-joint.

You can buy new B-body spindles from GM or find them readily in most wrecking yards. What you won't find are 1LE rotors in most salvage yards since they were fairly rare to begin with and highly sought after in the early to mid-90's. The 12" upgrade is a pretty easy, all GM upgrade that doesn't require any spindle modifications and will give slightly more performance than the factory 11" setups without a lot of cost.

Tobin
KORE3