I switched over to vac-brakes in 01'. Bought a master cylinder from carquest and relocated/welded a steel peg for the pedal assembly. I think they work great. She stops pretty darn well.
The S-10 parts I used were just for the rear cylinders - little more holding power. Have a t-brake now.
I have seen powermasters re-landscape a couple of times. Mine went out pulling into the driveway. My buddies GN did it at an intersection and ended up in someones front yard. His brothers went out in his neighborhood and had to use someones front lawn to slow the car. Reaction time when they go out has to be quick to apply the p-brake or downshift.\