Found a '73 Parts manual (score!)
340 with A/C Crank pulley: P/N 3671320 7 3/8"
WP pulley: P/N 3418227 5 5/8"
1.31 ratio for Max Cooling, which I believe I already have. I will confirm the WP pulley when I pull it apart. I am running at 210+* just right of the middle of the stock gauage (confirmed with Autometer gauge installed as well) without the A/C running with 180* high flow thermostat and 6 vane WP on a newly rebuilt engine ~700 miles ago. 26" Core 2 row radiator will be getting replace with HE 3 row US radiator.
