Wiseco K1607 Forged Piston Kit 74ci Panhead Shovelhead +.020 OS 9:1 Domed

The Wiseco K1607 is a high-performance forged piston kit engineered for Harley-Davidson 74 cubic inch (1200cc) Panhead and Shovelhead Big Twin engines. Featuring a domed piston design at a 9:1 compression ratio, this kit brings your top end to a +.020-inch oversize bore of 3.457 inches, making it an ideal solution for engine rebuilds and overbore restorations.

Each piston is forged from a high-silicon aluminum alloy using dedicated forgings that deliver a superior strength-to-weight ratio. Wiseco's aerospace-grade alloy construction provides greater durability over cast alternatives, withstanding the thermal and mechanical demands of high-performance V-twin applications. The dome profile is engineered for improved flame travel, while the precision skirt shape ensures stability and smooth operation within the cylinder bore.

Kit Contents:

• 2 forged domed pistons with coated skirts
• Chrome piston pins
• Piston rings — Hastings-style X-Ring package: .062" top ring, .062" compression ring, and .158" oil ring
• Retainer clips / circlips

Key Specifications:

• Bore Size: 3.457 in. (+.020 in. oversize)
• Compression Ratio: 9:1
• Displacement: 74 ci / 1220cc
• Piston Style: Domed
• Ring Package: Hastings-style X-Ring
• Manufacturer Part Number: K1607 (also referenced as 3457X / 4012P2)

Wiseco is the only U.S. aftermarket piston manufacturer that produces exclusively forged pistons, utilizing 3D design techniques and finite element modeling to optimize strength and minimize weight. The K1607 kit contains everything needed for a complete top-end overbore rebuild, delivering improved sealing, power, and long-term reliability.