Hello,
I have a 71 'cuda power disk brakes with a Midland Ross direct mount booster. What is the clearance for the booster rod to master cylinder piston. Thanks

i believe it's around .020-.030

For a GM product that would be the norm, but Chrysler's seem to work well with .060 (1/16 inch) clearance......

thanks for the clarification.
after flipping through a couple of FSM's, all i could find was the booster rod length from the master cylinder mounting surface at the booster to be .910-.920. there was no mention of clearance between the booster rod and the master cylinder piston bore depth.
not having a master cylinder handy to measure the piston bore, i didn't have a reference.

Wouldn't that be figured into the length?

i would assume [everyone knows what that word REALLY means ] so.
but not having a master here to measure the piston bore depth, [in my machinist tools, i have a "round bottom" stem set for my depth mics] i can't come up with the clearance that booster measurement would create in the master cylinder piston bore.

I made mine as they weren't so cheap and available years ago LINKY As for the clearance question,.030 should be adequate .060 IMO is a little to much but better to have enough than not enough. Do keep in mind more clearance leads to more pedal travel before braking begins. How much? depends on a number of variables. I usually shoot for .030 - .040" and call it good.