Do you understand that the rocker studs you are buying are 7/16". I'm bettin' the heads are tapped for 3/8-16 and you will have more machine work to do.
Tech: when was the last time you actually built a motor. All the heads are machined for a 7/16" thead in the head.
The only difference between a 3/8" SBC screw in stud and a 7/16" SBC screwin stud is the top thread diameter of the top part of the stud. one uses a 3/8" rocker and the other uses a 7/16" stud SBC rocker arm.
Either a 1.5 or a 1.6 ratio rocker arm gets it done, its up to you but wiht this street roller cam a 7/16" stud and matching 7/16" rocker arm is advised.
The Brodix bare Ik200 heads come with the valve job already done.
cleaning , checking clearances and valve sealing and correct assembly is all thats required.
Comp sells the spring seat cups. When using a spring seat cup in this head you will probabily want a +.100" length Manley valve and then shim as required for assembled spring height.
Comp cams and Brodix can advise. All you need to do is call.
this is the kit includes pistons all gaskets, rings bearings and the oil pump.