Jake - If you still have drum brakes on all four wheels, no valve of any kind is needed. Get a new M/C with the same bore as your existing one & it'll have the same stroke & pedal 'feel' when you stop. Your local NAPA can find one in their paper catalog. A bit of fab. work & you can make a adapter bracket to mount it on your truck. Make a pushrod of the proper length & get some new lines & re-plumb it to split the front & rear & you're done. Doug
