I have a very similar setup with the same problem. I attended the NSRA's "Nat South" over last weekend and spoke to the owner of "Fatmans Fabrication" about this problem. He suggested that anyone running disc front and drum rears not hookup the rear brakes to the proporting valve. He said it just robs pressure off the front discs. He also said a one time he put the adjustable proportioning valve on the front system but later learned to removed it as he always ended up with the valve wide open. I'm in the process of re-plumbing my system to see if it works.
Last edited by beltfed; 05/11/2012 2:47 PM.
