This item is for eight (8) .030-in. over bore Speed Pro (Sealed Power) forged flat top with 4-valve reliefs pistons and a cast piston ring set (Hastings/MAHLE) for Ford 390ci FE-series V-8 engines. P/N (8) L2291F-030 + 574-030. Feel free to message us with any fitment questions.

These pistons are Speed Pro's forged version of the 1966-1970 year model 4-barrel pistons. These pistons can be used as a performance upgrade in engines originally equipped with dish top pistons.

FALCON TECH NOTE: These pistons have a 1.776-in. compression distance, and some 390ci engines require a "shorter" piston; 1.66-in. compression height. Before ordering, make sure these pistons will work for your application.

Speed Pro forged pistons are made from extruded VMS-75 aluminum alloy that is forged under 3,000 tons of pressure to "near-net" shape. After that, they are machined to their final configuration. These pistons offer excellent strength and durability and are capable of taking the punishment that is dished out on the street and in competition.

PISTON SPECIFICATIONS

• Bore: 4.080 in. (at .030 bore)
• Stroke: 3.780 in. (stock)
• Connecting Rod Length: Stock; rods NOT included
• Piston Top Style: Flat top with 4-valve reliefs
• Piston Head Volume: +10.00cc
• Compression Height: 1.776 in.
• Piston Material: Forged aluminum
• Wrist Pin Diameter: .975 in.; pins included
• Wrist Pin Style: Floating or press-fit; pin clips included
• Ring Land Sizes: 5/64-3/32-3/16 (oil ring); rings included
• Notes: DurOshield coated skirts; 1966-1970 4-barrel design
• Usage: Street and mild strip; up to 150HP nitrous
• RPM Range: Idle - 6,500
• Compression Ratio (approximate): 10.1:1 w/67.1cc; 9.71:1 w/71.0cc; 9.43:1 w/74.0cc