I have a 1997 GMC Jimmy with a 502ci crate motor from GM Performance that has been fit with accessories from DemonMotivation. Additions to the engine include a Demon 850 carb, a complete pulley and bracket setup from March Performance, Taylor wires, and a custom-built air cleaner from Johnson's. Sanderson headers were treated by Performance Coatings and mated to 2-1/2-inch stainless exhaust tubing and Flowmaster mufflers. Smooth shifts are handled by a B&M-prepped Turbo 400 transmission sending power to the 3:90 Corvette rearend., Taylor, March, and Sanderson. The air cleaner was custom built by Johnson's Hot Rod Shop. The total horsepower adds up to 425. Yes 425 Horses!!!