To limit the cost of competition in Top Stock, IHRA mandates that each carburetor has a choke. This effectively limits carburetor selection to off-the-shelf stuff (with some minor tweaks or blueprinting). For this engine, a Holley 850 Double Pumper was used. On the dyno, it performed well with the factory-fit #68 jets. The floats were simply set up, and the engine starting making full-throttle pulls. Also, the 1-inch phenolic spacer is IHRA-legal.