72 Cutlass Brake Upgrade Options

[cdrod]

If you want a kit that works and includes readily available replacement parts, then give Tobin a call at Kore3 and buy his "325mm Big Brake" kit for A-body cars. This will reuse your stock drum hubs but they may need to be turned down to fit the C5 rotors. If you're on a budget, you can source most of these parts yourself from any auto parts supplier as all but the caliper brackets are over-the-counter factory parts. Keep in mind that this kit steps you up to 12.79" dia. rotors which will not fit factory rims (even 15" stock repop versions). You will need 17" at the minimum but most likely will need an 18" rim to fit over these larger rotors. You can download full size, fitment templates from the Kore3 website to check the caliper clearance inside the rim.



You can up your game even further with a spindle swap that raises the upper balljoint to improve the camber geometry. The factory A-body cars actually gain positive camber in a turn which is the opposite of what is needed for good handling; raising the upper ball joint causes the suspension to gain negative camber in a turn. This will require new upper control arms as well. As an alternative to the expensive tall spindles, you can use your stock spindles and steering arms but use tall upper ball joints to raise the upper pivot point. You can source the ball joints from Howe Racing and Pro Forged now make a tall ball joint as well. The Howes parts are rebuildable with replacement ball studs and you can get taller stud lengths up to +.9"; the Pro Forged ball joints are not rebuildable and come in a fixed +.5" & +.9" lengths. SPC makes a very nice adjustable upper control arm that works with the stock spindle and tall ball joint combo but will require minor modifications to frame supports to clear the control arms.

I did not buy the kit from Tobin for my car, as I chose to source the parts individually form Amazon, Rock Auto, and eBay. I did buy the stainless brake lines and aluminum hubs from Tobin. I used my stock spindles, SPC upper arms (#94320), Howe +.9" ball joints, Z06 red calipers and abutments (AC Delco#172-2263 & 2264), 12.79" C5 rotors (Centric#125.62059/060), I bought the caliper brackets used on eBay, and the hubs and hoses from Kore3. I measured the camber curve with this set-up on my '72 Olds 442 convertible (A-body GM) and found that the suspension gained approximately 0.8 degrees of negative camber for every 1in. of suspension travel. the camber curve was not linear as the negative camber gain increased with more suspension travel. Starting with 0 degrees of static camber at ride height, my camber was a full -4 degrees at full bump (compression) this was approximately 4in. of suspension travel.

I hope this info is helpful to you.

Rodney

[72cutlassS]

Seems like CPP spindle may not be the way to go. Unclear on any geometry or bumpsteer changes from what I researched.

If you want a kit that works and includes readily available replacement parts, then give Tobin a call at Kore3 and buy his "325mm Big Brake" kit for A-body cars. This will reuse your stock drum hubs but they may need to be turned down to fit the C5 rotors. If you're on a budget, you can source most of these parts yourself from any auto parts supplier as all but the caliper brackets are over-the-counter factory parts. Keep in mind that this kit steps you up to 12.79" dia. rotors which will not fit factory rims (even 15" stock repop versions). You will need 17" at the minimum but most likely will need an 18" rim to fit over these larger rotors. You can download full size, fitment templates from the Kore3 website to check the caliper clearance inside the rim.

You can up your game even further with a spindle swap that raises the upper balljoint to improve the camber geometry. The factory A-body cars actually gain positive camber in a turn which is the opposite of what is needed for good handling; raising the upper ball joint causes the suspension to gain negative camber in a turn. This will require new upper control arms as well. As an alternative to the expensive tall spindles, you can use your stock spindles and steering arms but use tall upper ball joints to raise the upper pivot point. You can source the ball joints from Howe Racing and Pro Forged now make a tall ball joint as well. The Howes parts are rebuildable with replacement ball studs and you can get taller stud lengths up to +.9"; the Pro Forged ball joints are not rebuildable and come in a fixed +.5" & +.9" lengths. SPC makes a very nice adjustable upper control arm that works with the stock spindle and tall ball joint combo but will require minor modifications to frame supports to clear the control arms.

I did not buy the kit from Tobin for my car, as I chose to source the parts individually form Amazon, Rock Auto, and eBay. I did buy the stainless brake lines and aluminum hubs from Tobin. I used my stock spindles, SPC upper arms (#94320), Howe +.9" ball joints, Z06 red calipers and abutments (AC Delco#172-2263 & 2264), 12.79" C5 rotors (Centric#125.62059/060), I bought the caliper brackets used on eBay, and the hubs and hoses from Kore3. I measured the camber curve with this set-up on my '72 Olds 442 convertible (A-body GM) and found that the suspension gained approximately 0.8 degrees of negative camber for every 1in. of suspension travel. the camber curve was not linear as the negative camber gain increased with more suspension travel. Starting with 0 degrees of static camber at ride height, my camber was a full -4 degrees at full bump (compression) this was approximately 4in. of suspension travel.

I hope this info is helpful to you.

Rodney

Rodney,

What are you running for rear brakes and master cylinder?

[jetmech442]

If you want a kit that works and includes readily available replacement parts, then give Tobin a call at Kore3 and buy his "325mm Big Brake" kit for A-body cars. This will reuse your stock drum hubs but they may need to be turned down to fit the C5 rotors. If you're on a budget, you can source most of these parts yourself from any auto parts supplier as all but the caliper brackets are over-the-counter factory parts. Keep in mind that this kit steps you up to 12.79" dia. rotors which will not fit factory rims (even 15" stock repop versions). You will need 17" at the minimum but most likely will need an 18" rim to fit over these larger rotors. You can download full size, fitment templates from the Kore3 website to check the caliper clearance inside the rim.

You can up your game even further with a spindle swap that raises the upper balljoint to improve the camber geometry. The factory A-body cars actually gain positive camber in a turn which is the opposite of what is needed for good handling; raising the upper ball joint causes the suspension to gain negative camber in a turn. This will require new upper control arms as well. As an alternative to the expensive tall spindles, you can use your stock spindles and steering arms but use tall upper ball joints to raise the upper pivot point. You can source the ball joints from Howe Racing and Pro Forged now make a tall ball joint as well. The Howes parts are rebuildable with replacement ball studs and you can get taller stud lengths up to +.9"; the Pro Forged ball joints are not rebuildable and come in a fixed +.5" & +.9" lengths. SPC makes a very nice adjustable upper control arm that works with the stock spindle and tall ball joint combo but will require minor modifications to frame supports to clear the control arms.

I did not buy the kit from Tobin for my car, as I chose to source the parts individually form Amazon, Rock Auto, and eBay. I did buy the stainless brake lines and aluminum hubs from Tobin. I used my stock spindles, SPC upper arms (#94320), Howe +.9" ball joints, Z06 red calipers and abutments (AC Delco#172-2263 & 2264), 12.79" C5 rotors (Centric#125.62059/060), I bought the caliper brackets used on eBay, and the hubs and hoses from Kore3. I measured the camber curve with this set-up on my '72 Olds 442 convertible (A-body GM) and found that the suspension gained approximately 0.8 degrees of negative camber for every 1in. of suspension travel. the camber curve was not linear as the negative camber gain increased with more suspension travel. Starting with 0 degrees of static camber at ride height, my camber was a full -4 degrees at full bump (compression) this was approximately 4in. of suspension travel.

I hope this info is helpful to you.

Rodney

This has a lot of good info Rodney.

Like you said, not sure if the 17'' rims will fit the 325mm rotors. The original D52's are a great caliper though, very stiff and way more piston area than the 6 piston Aero6, plus will fit under 15'' rims. Going with either a taller spindle(AFX), or upper/lower tall ball joints and the upper control arm to dial in settings will get you into good brakes AND great handling.

For reference, my 69 442 started out with the CPP stock disc brake kit front/rear. This got me into disc brakes the easiest, but the spindles they use don't have the best geometry and the rear calipers(d154) with integrated parking brakes are nearly impossible to adjust properly(I tried for 6 years).

I quickly went to wilwood D52's for better looks and less weight. Eventually I switched the rear D154's out with Wilwood D154's WITHOUT the parking brake and all my soft pedal issues were instantly solved.

Currently, I have ditched the CPP drop spindle, replaced with a stock spindle, installed Howe's upper and lower BJ's like Rodney said above. And the SPC upper and lower control arms. I'm running Tobin's (from Kore3) C6 Z06 adapters and the Aero6 caliper and 14'' rotor. I ran the SPC uppers for over 8 years, and only recently went with the SPC lowers since I found issues with my stockers. The SPC lowers allow me to get back my 2'' drop that I lost when going back to stock spindles.