Keith Black Hypereutectic pistons are favored for their improved power and reduced scuffing. The unique design & manufacturing processes combine to produce a rigid piston, which will rock less in the bore improving ring seal. These T-5 heat treated pistons also offer reduced thermal expansion, which allows you to run tighter clearances and allows the piston rings to seal better and minimize blow-by.

390 Hypereutectic alloy
Fully machined crowns and valve reliefs
Drilled oil drain backs
Full floating wrist pins
Triple wound spiral locks
Reflective alloy allows 2% power increase
Quench dome technology minimizes deterioration
Zero deck quench designs
Lightweight wrist pins

For Chevy 400 c.i. (4.125" bore x 3.75" stroke).

Item Details

C/R 58cc=12.3, 64cc=11.64, 76cc=10.0
Piston/Pin Weight: 475 g
Rod Length: 6.0", Ring Style: C

Charts

474-128 Instructions (PDF)

Ring Style Chart (GIF)

Specs

Comp Height 5.565" Rod - 1.561
Comp Height 5.7" Rod - 1.433
Comp Height 6.0" Rod - 1.13
Pin Diameter - 0.9272

CA Prop 65

CARB warning

Specifications

KEY SPECS
MFG. Part #	Select Oversize to see
Brand	Keith Black
Piston Style	Flat Top w/ 2 valve reliefs
Piston Material	Hypereutectic Aluminum

GENERAL
Piston Diameter	Select Oversize to see
Stroke	3.750"
Connecting Rod Length	6.000"
Piston Weight	475 grams
Piston Ring Style	C
Wrist Pin Diameter	0.9272"
Wrist Pin Weight	145 grams
Compression 58cc =	12.3 : 1
Compression 64cc =	11.6 : 1
Compression 76cc =	10.0 : 1
GTIN Code	Select Oversize to see
Sold in Quantity	Set