Mine *was* nearly straight as I recall:

[Linked Image]

One way to check is to see where the sensing arm is relative to the LSPV. If it it pushed clear to the top of travel due to the bend, then that is too heavy on the rear brakes and they will lock up first. Try bending it straighter to set the sensing rod a little below the full up position.

I got rid of mine many years ago:

http://www.4crawler.com/4x4/4R_suspension.shtml#ProportioningValve