Questions on a 94 305 TBI V8

[72c10step]

Here my friend and I were thinking we could just buy parts and bolt them on! He's bought a new cam, lifters, and timing gears so far for the motor, and will soon get pushrods, roller tip rockers, Z-28 valve springs, retainers, valve seals, and retainer locks for it as well. Unfortunately we're unsure of some stuff. Here goes the list. For a stock 94 305 TBI:

-What is the stud size for the rockers?
-What is the valve stem diameter? (for the valve seals)
-When you use roller tip rockers, do you have to machine the rocker stud boss (or whatever you call it), and use guideplates, or would it just be better to run stamped steel rockers?
-What is the installed height for the valve springs on this motor?

I can't seem to find most of this info, and I think I asked a question or two before, but its easier to get it all together at once. Also, if you have any more advice or words of wisdom, please let us know. I really don't feel like accidently destroying his truck.