The Melling CCS-1 solid lifter cam is available again- - - -a bit scarce, yes, but not "unobtanium" like the Elgin E-293S that is a clone of the 261/Corvette cam in every dimension except the lash settings. The CCS-1 has a longer duration on the exhaust lobe, which improves cylinder scavenging for better volumetric efficiency without creating a choppy idle. That makes the engine much more efficient at low to medium speed, and flattens the torque curve. Bump the compression up with a little bit of cylinder head milling, and the torque gets even better.
Jerry