Looking for an answer - I'm installing a '3rd' generation Bendix booster (from the mid 1970's) on a 58 Chevy 2-1/2 ton truck, in place of the '2nd' generation one it had on it. Brake line taps are all the same size (cylinders and booster), but I notice a difference in thread pitch - the orig. wheel cyl.'s have a slightly coarser thread than the taps on the newer booster. What's the explanation?
