Don Yenko built special high-performance cars at his Canonsburg, PA, Chevy dealership and the top-performing powerplants he provided in them were the "L72" 427 big blocks. Available in the late-1960s, these were potent 425-horsepower engines that featured rectangular port cylinder heads, 2.19-inch intake, 1.72-inch exhaust valves, 11.0:1 compression pistons, heavy-duty connecting rods, forged crankshaft, strengthened with 4-bolt main bearings.

The camshaft was of high lift design (.520-inch) and used solid lifters for maximum RPMs. A double-pumper Holley four-barrel carburetor (rated at 780 cfm with dual feed) was mounted atop an aluminum high rise intake manifold. These legendary engines were highly respected on both the street and the drag strip!

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