Product Summary

383, Flat Top w/ 2 valve reliefs Piston Style

  • Made from a durable, high ductility 2618 aluminum alloy
  • It is heat treated to high strength T-6 specifications for added durability
  • Comes fully machined with deep valve pockets
  • Features second land accumulator grooves and top land mini groove technology
  • Available in three sizes to custom fit your application

Key Specs

MFG. Part #
Piston StyleFlat Top w/ 2 valve reliefs
Piston MaterialForged Aluminum
Wrist Pin IncludedYes
Wrist Pin StylePress-Fit or Floating

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Formerly KB Forged Pistons. Starting with 2618 alloy heat treated to high strength T-6 specifications, these give you the best value for your money. Exclusive V-rib adds strength without adding weight but allows maximum cooling.

  • High ductility 2618 alloy
  • Dual forced pin oiling on most applications
  • Lateral gas porting on higher compression ratios
  • Fully machined with deep valve pockets
  • Second land accumulator grooves
  • Top land mini groove technology
  • Diamond finished skirts
  • Triple wound spiral locks

For Chevy 383 c.i. (4.000" bore x 3.75" stroke). Use Style C rings (1/16", 1/16", 3/16").

Item Details

C/R 58cc=12.0, 64cc=11.1, 76cc=9.8
Piston/Pin Weight: 609 g
Rod Length: 5.7"



  • Comp Height 5.7" Rod -  1.433
  • Comp Height 6.0" Rod -  1.13
  • Pin Diameter -  0.9272

CARB Warning

For race/ off road use or for use on pre-1966 vehicles.

Emissions warning: this part only legal for sale or use in California for racing (competition) vehicles which may never be used, registered, or licensed for use upon a public highway, or if installed in vehicles model-year 1965 or older; motorcycles model-year 1977 or older; or off-highway recreational vehicles (such as off-road motorcycles and all-terrain vehicles) model-year 1996 and older. Any other use renders the vehicle tampered and not legal for use on California public highways (any public street or roadway, public dirt road, public park, or publicly maintained right of way open to the use of the public for vehicular travel). Violations subject to $37,500 penalty per violation per vehicle, revocation of registration, loss of use on California public right of ways, and proof of correction for tampering. There are similar restrictions and penalties under federal law and the laws of all other states with penalties under federal law of up to approximately $45,268 per tampered vehicle and/or engine.


MFG. Part #
BrandIcon Pistons
Piston StyleFlat Top w/ 2 valve reliefs
Piston MaterialForged Aluminum
Wrist Pin IncludedYes
Wrist Pin StylePress-Fit or Floating
Speedway Motors Catalog Part #474-728
Piston Diameter
Connecting Rod Length5.700"
Piston Weight476 grams
Piston Ring StyleC
Wrist Pin Diameter0.9272"
Wrist Pin Weight133 grams
Compression 58cc =12.0 : 1
Compression 64cc =11.1 : 1
Compression 76cc =9.8 : 1
Sold in QuantitySet