Product Description


This item is for eight (8) .030 over bore Speed Pro (Sealed Power) powerforged 30cc dome pistons and a cast piston ring set (Hastings/MAHLE) for Chevrolet 454ci (7.4L) big block V-8 engines. P/N (8) L2349F-030 + 683-030. These pistons are Speed Pro's version of the 1970 454 LS6 pistons.

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


  • Bore: 4.280 in. (at .030 bore)
  • Stroke: 4.000 in. (stock)
  • Connecting Rod Length: 6.135 in. (stock); rods NOT included
  • Piston Material: Forged aluminum
  • Piston Top Style: Dome with single valve reliefs
  • Dome Height: .265 in.
  • Dome Volume: -30.60cc
  • Compression Height: 1.645 in.
  • Wrist Pin Diameter: .989 in.; pins included
  • Wrist Pin Type: Press-fit only
  • Ring Land Size: 5/64-5/64-3/16 (oil ring); rings included
  • Notes: 1970 454 LS6; closed chamber heads; DurOshield coated skirts
  • Usage: Street and milt strip; up to 150HP nitrous
  • RPM Range: Idle - 7,000
  • Compression Ratio (approximate): 12.2:1 w/100.9cc; 11.2:1 w/109.4cc; 10.2:1 w/119cc

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