I have a 1990 1500 series full size Blazer 4X4. I lifted it with a 4" suspension lift and ever since, it pulls when you brake. The faster you stop, the more it pulls. It has had all brake parts replaced including the proportioning valve. I took the blocks that came with the lift out and put in a set of 4" lift springs on the rear. I noticed that the right side of the vehicle will leave a skid mark after a panic stop with a right curve at the end of the skid. There will be a very light skid on the left side that is about 1/10 the length of the right side. I still wonder about the proportioning valve, but can't prove it. Does anyone have any suggestions? Is there a way to make sure that the proportioning valve is centered? I have been fighting this for about 6 months now. I am considering having it stolen so I can buy a reliable vehicle.