But what about the power increase over World's own LS engine? It wasn't all due to a simple port job on the heads. Mitchell reminded us of the differences between the SBC and LS cylinder-block designs. The LS block has a deep-skirt design (also known as a "Y" block"), while the small-block casting extends only to the crankshaft centerline.
The LS block design enhances overall rigidity, which is particularly helpful with OEM aluminum castings, but it creates considerably more crankcase windage than the small-block. The Motown II block is plenty stiff to begin with, with thicker-than-stock key features (bulheads, "China" walls, and more) and four-bolt mains.
"Windage makes a huge difference," Mitchell says. "With this combination, you've really got this best of both worlds-an affordable, performance-oriented bottom end and the great breathing of LS heads."
The implications for the Motown LS are far-reaching for street and racing enthusiasts-and exciting. Just imagine this monster in a C3 or C4 Vette.
World Products deserves an achievement award for the Motown LS, and enthusiasts everywhere are the beneficiaries of the company's progressive attitude toward building big power.