KB Hypereutectic Single Piston for Ford 416 ci. using Ford 351W Block w/6.200 in. Rod, 4.075 in. Stroke, 4.030 in. Bore

Name: KB Hypereutectic Single Piston for Ford 416 ci. using Ford 351W Block w/6.200 in. Rod, 4.075 in. Stroke, 4.030 in. Bore
Brand: UNITED ENGINE MACHINE
SKU: 648-KB261.030-1
Price: 113.63 USD
Availability: InStock

^$113⁶³

1 left in stock

Ships on Sep 14, 2026

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Ford 416ci

Flat Top Piston

Use with Ford 351W Block

KB Hypereutectic Single Piston for Ford 416 ci.

Ford 351W Block

6.200 in. Rod

4.075 in. Stroke

4.030 in. Bore

Use Ford 400 Crank Offset Ground to 4.075 in.

Pre 1971 Blocks Only (Milled .020in.)

Flat Top w/2 Valve Reliefs (+6.5 cc)

KB Hypereutectic Single Piston for Ford 416 ci. Using 351W Block:

Replacement Piston for: KB261.030
Alloy: Hypereutectic 390
Bore: 4.030 in.
Crankshaft Stroke: 4.075 in.
Connecting Rod Length: 6.200 in.
Deck Height: 8.206 in.
Compression Height: 1.608 in.
Pin Size: 0.927 in.
Pin Location: Centered
Intake Valve Relief: 0.266 in. Depth / 2.120 in. Diameter
Exhaust Valve Relief: 0.254 in. Depth / 1.880 in. Diameter
Top Landing Height: 0.275 in.
Ring Grooves: 1/16 in. Top; 1/16 in. Middle; 3/16 in. Bottom
Compression Ratio: 13.2:1 w/55cc Heads; 12.4:1 w/60cc Heads; 11.2:1 w/69cc Heads

100% CNC Machined Pistons

New high silicon alloys and diamond tooling have give Keith Black designers the material and equipment for performance breakthroughs in engine design. KB pistons are 100% CNC machined and T-6 heat treated from 16%-18% silicon Hypereutectic alloy. Features include drilled oil returns and pin oil supply, .072'' spiral wound retaining ring, 100% diamond turned, compensated high strength ring lands, high top ring location, 360° pressure pin oiling, diamond honed pin hole and lightweight rigid rib skirt design.

Features:

390 Hypereutectic alloy with 16% Silicon
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
Sold in Sets (except when noted as 1 piston per package)Click here for reference guide to piston top designs

Part TypePiston

Product LineUEM Pistons KB Signature Series Hypereutectic Ford Pistons

BrandUNITED ENGINE MACHINE

Package Height5.0

Package Width5.0

Package Length5.0

Weight2.12 PG

Part CategoryPerformance Parts

Piston Head Volume (Cc)6.5

Piston Ring Thickness (In.)1/16 x 1/16 x 3/16

Wrist Pin StylePress-fit or floating

QuantitySold individually