For guys competing in unlimited-displacement race classes like IHRA Pro Stock or NHRA Top Sportsman, there really is no replacement for displacement. In these niche worlds with no limits, Sonny’s Racing has long been the mountain motor leader. Founder Sonny Leonard has specialized in big, big-block Chevy-based motors for more than 41 years, building ever larger and more radical combos that in their most advanced incarnations bare only a superficial resemblance to Chevy’s original Rat.
And by “big” we don’t just mean a wussy 496, a puny 540, or even a wimpy 572. No, we’re talking giant, megafauna, Pleistocene-epoch massiveness here—you know, 1,000,000 years BC big, 1,000-pound saber-toothed tiger big, 10-foottall beaver big. Sonny’s motors start out around 611 ci and have grown ever larger, with standard production mills now…