I've spent a lot of time searching but can not get a clear answer. My Firebird originally came with drum brakes which I changed to LS1 disks on all 4 corners. Some posts state that a new combo valve is needed while others state that just changing the spring inside is all that is needed. To complicate matters I've read that drum valves leave slight residual pressure to keep the brake cylinder cups flaired. So can someone please tell me what needs to be done? Thanks!

 

73 views.... anyone?

 

If I purchase a $100+ combo valve, and I find out later that all I had to do was replace a spring, I'm going to be a bit cranky..... just saying...

 

Replace the spring or put a manual adjust proportional valve on rears. Try the spring, if you don't like it get and install the valve.
https://www.thirdgen.org/propvalve