Solid lifter cam.

How big of a cam (lift & duration)? The smaller it is, and the lower the RPM's that you run, the less you need geometry correction (unless it is reeeealy awful to start with). Lot's of engine run fine without it; the correction optimizes the lift and makes the valve accelerations truer to the cam profile, which can reduce valve float tendencies.

You can get an idea of how good or bad the present geometry is with roller rockers very easily. Look at the scrub pattern on the valve stem tips and see how wide it is. The best you could do will look like pix #3 in post #20 in this thread:
EQ heads, Chevy rockers and what studs?