Master Cylinder Change?

I just read a discussion on another thread about the brake pushrod length (search for it). Some say that the aluminum cylinders have shorter travel, or maybe a different starting position and that the $45 adapter accounts for that. They say if you don't use the adapter, you need a shorter pushrod. Seems suspect since the aluminum MC looks like it may have more piston travel.

I'll investigate further on my Valiant w/ manual brakes. I did quickly check the installed pushrod depth against my original MC and seemed "close enough", but that was just a tape measure effort (~1/4"). The final answer is when all installed. The MC piston should go in just slightly to keep the brake light switch off, but not enough that you lose pedal travel. You can adjust the switch a little, but you don't want the pedal coming too far out either. It should sit near the accelator level so you can move your right foot between them easy, though I often drive an automatic with 2 feet in touchy situations, despite what was taught in driver's ed. I just re-program my brain back to go kart driving days.

If installing power brakes, like I did on my Dart, if you use both the booster and MC from a cloud car (on factory Dart brackets), those boosters have an adjustable pushrod between the booster and MC, so easy to get it perfect.