[Steve Vos]

I have a 69 gmc with 72 front discs and the 11 5/32 rear HD drums on 5 bolt axles. The rear brakes came off a 73+ axle. They all bolted up to the rear housing great which is off a 70 and converted to 5 bolt. The problem I have is my pedal effort is too high and the stroke is too short compared to my 86 Silverado. I have good vacuum from the 396 engine. I used a 72 master and booster and a proportioning valve of unknown origin. I looks like the valve for an 81-87 Chevy listed on the inlinetube.com web site so I think that may be what it is. I also see these brakes listed in the 73-87 LMC catalog. In there they list different masters, proportioning valves, and boosters based on the larger drums. I am wondering if my setup is not correct. Does anyone out there know about this and what would work? Do I need to match the parts to these particular rear brakes? If I have to change boosters I would like to find a smaller dia to get more valve cover clearance. Any recommendations there?

Thanks in advance for any help.