That's what I did when I swapped to a Magnum.
I tore it down to just crank, pistons, and rods. Had them tear it down and hot tank it, polish the crank, new main, rod and came bearings, hone and new rings. I took it from there and finished the build with a reground cam from Oregon Cam Grinding, Edelbrock 2.02 heads, air gap and carb.
At first I ran an electric fuel pump but later bought the Hughes Cam extension and switched back to a mechanical pump.