78 Corvette brake conundrum...

Master cyl is unhappy...there is more to bench bleeding a master cyl then pumping...the worst thing is those plastic fittings and rubber hoses...every time I sold a master cyl with that kit in the box there was a 75% chance it was coming back to me as defective.I've sold over 10000 master cyls probably more...it takes 3 pumps..that's it.