Building boost with rear brakes locked?

[fastjack1]

How do you modify the proportioning valve to get full pressure to the rear brake cylinders so I can build and hold more boost at the tree? My understanding is some part or piston can be removed from the proportioning valve. Thanks.

 

[Red Regal T]

Now, here's a link tht shows the modification for rear disc brakes. I don't know if that helps you, but I'd think what you could do is simply change over to an adjustable proportioning valve. May be the simplest answer. You could also set your parking brake to help.

http://www.turbobuick.com/forums/2503073-post4.html