Keith Black Hyperutectic 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=14.5, 64cc=13.3, 76cc=11.4
Piston Weight: 583 g
Rod Length: 5.7", Ring Style: A

Charts

474-127 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

Guides & Documents

Pistons Installation Instructions (474127)

Pistons Technical Information (474127)

CARB Warning

For race/ off road use only

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. 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.

CA Prop 65

CARB warning

Specifications

KEY SPECS
MFG. Part #	Select Oversize to see
Brand	Keith Black
Garage Sale Type	Closeout
Piston Style	Dome
Piston Material	Hypereutectic Aluminum
Wrist Pin Included	Yes
Wrist Pin Style	Press-Fit or Floating

GENERAL
Piston Diameter	4.155"
Dome Height	.100"
Stroke	3.750"
Connecting Rod Length	5.700"
Piston Weight	583 grams
Piston Ring Style	A
Wrist Pin Diameter	0.9272"
Wrist Pin Weight	145 grams
Top Ring Thickness	5/64"
Second Ring Thickness	5/64"
Oil Ring Thickness	3/16"
Compression 58cc =	14.5 : 1
Compression 64cc =	13.3 : 1
GTIN Code	Select Oversize to see
Sold in Quantity	Set

Ratings & Reviews

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Yes I would buy them again

5.0

3 years ago

Nos455

Plainfield indiana

Verified

Got the kit and it had the wrong pistons in it but customer service did a great job and got me taken care of and got me the right ones sent out

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