All Chevrolet ACT Prolite Flywheel - 6004551

All Chevrolet ACT Prolite Flywheel
Preferred for Road Racing or minimum inertia
Fits: 1955-1985 Chevrolet All 4.3L 265" thru 7.0L 427", all V8 (exc 400"), 2 pc rear main seal, 153 tooth,10.4" clutch

XACT Flywheels

Quicker acceleration and increased throttle response

Maximum gear life - gear will not wear out or fall off

Serviceable - can be resurfaced with no need to purchase additional parts

Chrome-moly forgings three times more rigid than aluminum

Longer lasting because of heat treated friction surfaces

Excellent heat capacity from retaining adequate material behind the friction surface

Trouble-free single piece design

SFI certified to insure safety


Prolite Flywheel

Preferred for Road Racing or minimum inertia

Quick throttle response and acceleration

Lightest with lowest inertia

Reduced drivability

Streetlite Flywheel

Preferred for Street and Drag Racing

Improved throttle response and acceleration

Considerably lighter than stock

Most durable flywheel available

Good drivability

Key Features

ACT flywheels are lighter, stronger and safer than stock cast flywheels to meet the needs of both enthusiast and hard core racer.

Material is properly distributed for maximum strength, lower inertia, good heat tolerance and rigidity.

One piece construction allows less opportunity for failure and provides uniform efficient heat transfer from the clutch disc. No more warped inserts or loose ring gears.

Integral ring gear permits more weight reduction where it matters most and eliminates the chance of gear breakage or separation from the flywheel.

Precision machined threads will not easily strip out or get damaged like those found on aluminum flywheels.

ACT engineers XACT flywheels using the latest CAD and FEA (finite element analysis) software to evaluate all design alternatives to get the best results possible.

By hot forging chrome-moly steel, each flywheel yields an ultra fine centralized grain structure that is superior in strength to any other manufacturing method.

Timing marks are precisly located and clearly displayed (when applicable).

ACT gives extra effort to strategically slot XACT ProLite flywheels to lower inertia without sacrificing strength and heat dissipation.

ACT heat treats the entire forging for strength and toughness, and induction hardens their ring gears for longest gear life.

XACT Flywheels are certified as meeting SFI Specification 1.1. XACT Flywheels are legal for competition in all racing organizations where SFI certification is required.

Ring gears are cut with lead-in chamfers for better starter engagement and prevention against rounding off gear teeth.

Engineers at ACT demand tight tolerances for fit, concentricity and parallelism so that flywheels will have an exact fit onto the crankshaft, and operate smoothly even at extremely high rpm.

All flywheels are CNC machined and dynamically computer balanced for super smooth high RPM reliability.