I swaped rear ford explorer brakes (ford 9" rear end) on my 87 firebird that had rear drums. I swapped the proportioning valve from a 92 that had 4 wheel disks and changed the threads. Now I am not sure but it seems as if I hardly have rear brakes. I have not put the car on the ground or taken it for a ride yet, but on jack stands I can hold the brake as hard as possible and rev the car and the axels start turning at about 1000-1200 rpm does this seem low? Should I change out the master to the 4 wheel disk one that has a .05" bigger rear piston?

I bled everything: master,foot bled, vacuum bled, and gravity bled.

Please help I have a race coming up this Saturday and need to get the car on the road.

 

any one?

 

Might be low.

Go drive the car and break in the pads and rotors and see how they are then.

 

might be best to ditch the stock prop valve and get an adjustable. Maybe the Ford brakes have different pressure ratings/specs and need to have adequate pressure to them to work properly. Or maybe you still have a little air in the lines. Id try re-bleeding them again, try pumping about a half bottle or so worth of fluid out through the bleeders. If you do ditch the stock prop valve though, let me know. I need one for my LS1/PBR swap