On the TrickFlow 240 heads I used stock stamped steel rockers for at least 6,000 miles with no troubles. The next year I used bushed Crane ductile iron rockers for 1300 miles, only issue seemed to be some valve tip wear. I didn't really do much checking other than side and rocker to retainer clearance. When I put this engine back in I figured I ought to stop messing around and got Harland Sharps and started checking geometry and decided to use a shaft relocation kit from B3 racing engines.

I used a carbide bit in a die grinder to elongate the holes with my Harland Sharp kit for the B3 relocation kit. This has allowed me to keep using studs for rocker hold downs. If I recall correctly, if using bolts as hold downs, the grinding might have been unnecessary or at least less extensive
Mike @ B3 racing engines was very helpful, and I would check with him as I'm sure he may have a more elegant solution than what I did. Also depending on how far the rocker shaft is moved any grinding might be unnecessary.