Factory 68-71 340 puts 325HP on GM Dyno

Per the old Direct Connection Chassis Manual back then for Super Stock NHRA factored the 1968-1970 (AVS) 340 at 295, 1971 (TQ) at 305 and 1970 (6 Bbl) at 325, and the 1972-1973 (TQ) at 275.

Prior to SAE net ratings in 1972 most horsepower figures were pure ballyhoo driven by the marketing departments.