rebuilding a rebuilt slant

72_dart,
Read up a bit on cams. If a later motor, yours probably has hydraulic lifters. If you pull the valve cover and the rockers have no adjuster bolts, it is hydraulic (view photos first). If so, I don't know if you can change it to mechanical lifters and cam. They changed the oiling system I recall. You can probably go that way (not the other), but would need rockers from an earlier motor. Not sure you can get performance hydraulic cams for a slant, so maybe no choice but to swap.