I haven't any issues with the power master yet they are working great right now but don't want to be on the power tour when the first problem pops up either. I am going to be putting on the S-10 wheel cylinders too.
I just drilled mine 1.25 inches lower and put in a 7/16 Clevis 1 inch long so I can go back to PM without changing pedal but the main reason is I just bought a new rubber pad for the pedal
I actually ordered a billet check valve with an fitting on it to replace the plastic one and will drill and tap back of dog house then connect them with braided hose to make sure it doesn't blow off
Don't have emission tests here but I am trying to keep the engine bay to look as untouched as possible. The alky is the only thing that looks out of place until I put on the vacuum brakes.