This high performance muffler has been developed for vehicles with 4" sidepipes such as 1965-74 Corvettes or vehicles equipped with Hooker Super Competition Roadster and Side Mount Headers. These mufflers produce an average of 23% more power than open headers and feature a high-flow, perforated core that operates at 99% efficiency. High temperature packing material absorbs noise while producing a powerful mellow sound. These mufflers, as tested on a 1968 Corvette with a 427 cu inch engine increased horsepower by 40 at a peak of
5500 RPM and 20 ft.-lbs. at peak of 4500RPM versus a leading aftermarket undercar header/turbo-style muffler combination. The outer case is constructed of durable 16 gauge aluminized steel protected by electrostatically applied high-temperature black paint. The inlet/outlet is a 2.5 perforated core in a 4" casing.
Holley has been the undisputed leader in fuel systems for over 100 years. Holley carburetors have powered every NASCAR® Sprint® Cup team and nearly every NHRA® Pro–Stock champion for four decades. Now, Holley EFI is dominating the performance world as well as our products for GM's LS engine. Holley's products also include performance fuel pumps, intake manifolds & engine dress–up products for street performance, race and marine applications. As a single solution, or partnered with products from other Holley companies - Hooker Headers, Flowtech Headers, NOS Nitrous, Weiand, Earl's Performance Plumbing, or Diablosport - Holley products can give you the edge you need over the competition.