Hope that this information will help in your quest for answers, reguarding the brake cylinders, On the older kit the kits were shipped with Cleveland brake cylinders, and the body was quite wider, hince the unit had to be mounted upside down for pedal clearence issues. In time the kits were now being supplied with narrower units made by Matco, now they can be mounted in the upright position. So now you see why there is a difference up, or down.
The older units that were mounted upside down were hard to bleed, so the solution to this problem is to disconnect the shaft from the bottom of the brake pedal tie the units in the upright position, bleed the lines then reattach the brake shaft to the pedal.
Cheers, TX RV-4