Ok, I have been going through all the posts that I have been able to find in regards to increasing my braking ability. I am not sure which way to go here. I have 72 GMC Jimmy with the stock 1/2 ton MC and booster. I have 3/4 ton 14blt ff rear and dana44 front with the 3/4 ton brakes all around. I replaced all the front brakes parts; rotor, calipers in front and rear brake cylinder and pads and seals! When pressing on the brakes I have to stand on the brakes to stop on the road, and really hairy going down hill. To my recollection I don't recall EVER being able to lock up the tires to skid. Should I replace the master cylinder and booster and if so go to the 1/2 ton or should I upgrade to a 3/4 ton to accomodate the 3/4 ton brakes? One interesting thing I did read was making sure the vacuum hose to the booster was the correct type, I will have to check that out.