Chevrolet Flywheels Tech Info:

There are two different diameters flywheels used on
Chevrolet Small-Block V8, Big-Block V8, and V6/90-degree engines.
Large flywheels are 14" in diameter, and have a 168 tooth ring gear.
Small diameter flywheels are 12-3/4" in diameter, and have a 153 tooth ring gear.
The difference in flywheel diameters requires two different starter housings.
Starter noses used with large diameter flywheels have two long offset bolt holes.
Starters for small flywheels have two bolt holes (one long) & (one short)
which are paralleled to the back of the block.
Most Chevrolet blocks are drilled for both types of starters.
If you change your Chevrolet's flywheel, from a 12-3/4" (153 Tooth ) to a 14"(168 Tooth)
you will need to be sure to install the correct starter for the flywheel diameter.
Most of the small high torque mini starters may accommodate both
12-3/4" 153 Tooth & 14" 168 Tooth flywheels.

Click Here To View Our Chevrolet High Performance Gear Reduction Starter Area

!! WARNING !!
On The ALL GM PMGR Starters DO NOT INSTALL A JUMPER WIRE FROM THE BATTERY TERMINAL STUD AND
THE SOLENOID ACTIVATION STUD ON THE STARTER.
In some older cars some may experience a HOT Starting Condition where the solenoid will not activate when the vehicle is hot, and may want to use a auxiliary starter relay to activate to solenoid.
INSTALLATION OF A JUMPER WIRE FROM THE BATTERY TERMINAL STUD AND THE SOLENOID ACTIVATION TERMINAL WILL CAUSE THE STARTER TO STAY ELECTRICALLY ENGAGED ONCE THE SOLENOID IN ACTIVATED RESULTING IN SEVERE DAMAGE TO THE STARTER AND MAY EVEN CAUSE DAMAGE TO THE FLYWHEEL!!