I've done plenty of searches, and am just as confused, I have an 89 RS with Drum, converting over to 87 Iroc 10 bolt. from what I understand my MC is the same, and the e-break cables will need replaced. now my questiion is the P-valve, I've read where i could use the one I have with no problems and others say to change due to the fact that the disk dosn't need that much pressure...everyone seems to have an opion on this but no for sures...

Also if I need to get a new valve where do I find one? cheep!!!

Thanks,
Ken

 

Cheap? From the donar vehicle that you're getting the rear end from....
Otherwise, visit your GM parts dealer.

Personal experience; I replaced the old drum proportioning valve with a brand new and correct disc brake p-valve for brake bias and peace of mind. You do what you want but, Please dont cheap out and put the rest of us at risk by not matching brake components!

 

Thats just it, I don't want to put my life at risk, thats why I'm asking...

donner car, don't have one. bought the rearend, so are the P-valves the same on the 89RS drum vs the 85 disk, will the 89 work? or do I need to get a new one. if I need to get a new one where can I find one?

thanks again...