lightest a-body??

The 318-3 was a heat-treated and shot-peaned crank identical to the 273, in my hurry typing about the engine in Grable's car, I made a mistake, as the crank they used was the 301 "Poly" crank from 1957/58 A engine, which was a different crank altogehter. Sorry 'bout that.
No harm, no foul. Sounds like an interesting build.