340 Max HP Potential with X/J heads?

Ok, is that with cast heads? Factory or ported? X or J?
915 J
11/32 stem
+.100
2.02/1.60
Healthily ported...roofs raised, press in bronze guides, guide bosses reshaped, intake windows widened to.030 thin@ the pushrod holes..etc Hardened seats- intake and exhaust, chambers worked some and opened to the bore.