Originally Posted by moparx
then there is the question of a single diaphragm or a dual diaphragm booster, and the booster size. beer

This right there is a great point!

I have a dual-chamber booster on my Dippy coupe, the hydraulic flat tappet cam only pulls about 7" of vac, and it's dipped lower, right down to 5" at idle numerous times (mostly when I was tuning and trying a few things here and there), point being: my brakes have NEVER gone away!

This is with discs up front and drums at the back.