Whats wrong with this brake combo
 

My friend has an early 90's S10 Blazer its got a 355 ,turbo 350 with a 10 bolt in it. The brakes are disc / Drum. Stock I think. He had a Corvette 1" master on it with no booster (not enough vacuum). The brakes are hard as a rock with hardly no pedal travel. He said its like stopping a Mac truck. It has no residual or prop valve in the system. He changed to the factory S10 brake master and still the same. Not sure if it was for manual or power set up. Need help fixing. I think the brake set up came from Master brake systems. They told him to use that Corvette master. Does it make a difference which part of the master you connect to, front bowl for the rear and rear for the front?
Thanks

Presumably you have the C3 Corvette 1" bore MC, so that should be front/front and rear/rear for the plumbing connections. As for the feel, I don't know what to tell you other than the factory power applications came with 24mm/36mm (power) or 24mm/31.75mm (manual) quick take-up type MC's, which are effectively a smaller bore MC by ~12% from the 1" bore unit he's running now in a manual configuration, regardless of which unit he tried.

I'm guessing two things would help his situation, the first being a smaller bore master cylinder and the other being a better, higher coefficient of friction pad. Even with the MC issues going on, it sounds like he may have pad issues to me as well, but I'm just spit-balling here.

Tobin
KORE3