Reply to "1970 Boss 351"

Dennis, note they said "Boss 351-C " which as you know is quite different from garden-variety Clevelands factory-installed in every U.S. Pantera, and most Euro Panteras, too. 1971 was also right before the Truth In Advertising laws that drastically lowered published horsepower ratings from mfgrs. DeTomaso was one of the mfgrs that routinely inflated horsepower ratings in all their cars by 10-50%.
All factory Pantera-Clevelands got hydraulic lifter cams, non-adjustable valvetrains, a lower compression ratio and a host of detail differences that cost power. If you indeed have a Boss engine in there, someone changed motors. By late '71, Ford owned DeTomaso outright and simply wouldn't pay for extra-cost Boss engines.... and their warranty!
With deference to HRM, all Cleveland rods were indeed 'forged' but of low-carbon 1041 steel that cannot be heat treated. Boss rods were identical to other Cleveland rods, only being selected by brinnell-impact testing for toughness. Enthusiasts of the day spent literally months and thousands of dollars to bring their engines up to 'advertised' horsepower ratings; I was one and I never did quite achieve the ad-exec's typewriter power levels.