C5 Brake Experiences?

[ElkySS89]

I'm looking at switching to C5 front brakes and I had some questions. Not so much about fitment but about ways to make them work better.

Those who have them, what is a good rear brake setup that provides a good balance with C5 fronts?

Is there a better master cylinder I should use or is the stock, early GBody one fine?

 

[81cutlass]

I've used LS1 fronts on 2 cars, calipers are almost identical so my experience should apply

I've used 98-05 blazer rear disks on one car and 93-97 LT rear disks on another
I've used a cast iron disk/disk riviera 80 master on my 81 cutlass and a late B body wagon aluminum master on my 86 GP with the lines flipped front to back
Stock disk/drum master has performed badly on both setups with various combos of big disks on the front with or without disks on the rear.

If you have an OEM booster that is pre 82 it probably has a small pilot that won't allow the aluminum body master to seat properly.

Both work great and I have used the stock prop valve with no issues. I can lock up all 4 on my GP (245 front 275 rear 200 treadware tires) from a 30 roll. My cutlass can hold about 3-5psi brake boosting at the track with a turbo buick setup before pushing through the brakes.

 

[ElkySS89]

Is there a performance difference between and early and late Gbody booster?

 

[81cutlass]

Not that I have noticed. GM just changed the pilot diameter on the booster to be larger in 82.

I prefer the 82+ masters because they are aluminum and don't rust like the cast iron ones but they both work fine to my uncalibrated brain.

I don't have the master diameters off the top of my head but you can check them on Rock Auto. I seem to recall the 80 Riv disk/disk was similar to the 90 B body wagon disk/drum.

 

[ElkySS89]

I know there's a difference in the masters from those years because they had quick take up calipers while the early ones didn't. At least, with G-Bodies. I don't know about B-Bodies.

So, C5 fronts, Blazer rears, and disk/disk master is the combo that works best for you? I'm also curious about the all new rears from CPP but they come in a few different sizes