I do like the idea of 1.6 rockers. One thing that captures my attention is we haven't been told what heads you have and valve size. I know you said they ran well on stock and super stock engines. Does it have 1.94 intake valves or 2.02's. Increasing lift with the smaller bore 283 (+ .060) can experience shrouding and possible material contact depending on the chamber size and valve size. If the valve will not interfere when open, consider shrouding and if it may pose a problem for your application.