Does anybody have or know of a place to find out the piston sizes in our master cylinders for both disc/drum and disc/disc for all years? Also, what is the prop valves set at?
As of right now I've got stock front brakes and aluminum drums in back. Car stops but it's scary, so I bought LS1 front brakes. Now I need to find information about our master cylinders to see if I need a new one. I don't know if I'll be able to find ls1 rear brakes before I install the ls1 fronts so obviously I'm going to run an adjustable prop valve either way.
Any and all experience, opinions, and thoughts welcome. Thanks in advance.
edit: I just found a site that spoke of a 10 lb residual valve. This is probably required if I got a disc brake master cylinder. So maybe I can just use the current master cyilnder until I get new rear brakes....any thoughts?
Oh yeah, and what is our pedal ratio?
J50 vs J65 cylinder sizes?

 

The drum and Al caliper rear discs got the same MC with 15/16" bore. The Iron caliper rears got 1" bores. The LS1 fronts should work fine with rear drums and the drum prop valve, although an adj valve is always a good idea if you feel you need more power to the rears. Your drum MC should not have to be changed even when you goto rear discs.

 

https://www.thirdgen.org/techbb2/sho...aster+cylinder

 

Arguably one of the best pieces of information that anyone ever dug up!

As to prop valves, I had read (somewhere, can't remember where) that on a 4-wheel-disc system, the prop valve doesn't do any proportioning... that it gives equal pressure to front and rear brakes. Anyone know if that's true?