I'll be straight with you, dude.
The SpeedMaster/ProComp/et al is junk. And yes, it's cheap Chinese junk, just like the lifters you bought.
I don't use their stuff, but have seen plenty of it fail: heads can't pass a pressure test, seats need valve job, guides fall out, roller rocker arms spit out needle bearings, distributors fail.
It's cheap for a reason. You play the game, roll the dice, and see if it works for you.