[tbplus10]

Yes you can adjust the porportioning valve. The actuating arm has a threaded adjustment on it that will increase or decrease rear braking force when adjusted. Be careful when adjusting it, it's real easy to get to much rear braking force and cause the rears to lock up. Find a road with very little traffic to test the brakes.

 

[tbplus10]

Yep, thats the best method for adjusting them.

I've been through Georgetown on my way to Round Rock a few times, I didnt think they had any busy stretches of road down there.

 

[tbplus10]

The EBCM system operates on inputs from the front brakes, rear brakes, and transmission, it's tied into the anti-skid system. Unlike the older systems that are mechanical. Inputs can be manipulated at the computer with the proper equipment, i.e. GM's diagnostic scan tool. Another way is to remove the EEBC and replace it with a manual porportioning valve then trick the brake system electronics so you dont have an ABS light.
Troll some of the drag race websites I know more than a few of them have deleted the EBCM and used manual BPV's and looped the system to stop ABS lights.

 

[tbplus10]

Thats my understanding, but how much the brake bias can be adjusted is a mystery. ABS can also be adjusted slightly and I'm only guessing here but I would think brake bias and ABS signals would be tied together.