First hand knowledge...

my machine shop said their kit was perfect right out of the box, didn't need any machine work to fix anything. I literally had the assembly balanced, and then put it together.

I saw a friend use their aluminum roller rockers. They failed within a couple thousand miles. I would NOT use any of their valve train gear.

how's that compare to a Made in the US brand like Edelbrock? I've used 3 sets of RPM heads. one big block set, was great out of the box. first set of small block had such bad intake valve jobs, I could see daylight through the seat when the valve was "closed" had to spend $130 to have all the seats fixed. Second set of small block heads, my machine shop said looked great, had no issues.