To allow teams to compete in the KCRP Pro Late Model division with their GM 604 Factory Sealed or GM 604 ‘Yellow Book’ rebuilt motors, we conducted a dyno test at RW Racing Engines, in Seymour, Tennessee, by owner Robbie White.

Here are the provisions in place based on our dyno test to equalize performance of the GM 604 to that of the GM 602.

All GM 604 Factory Sealed, or GM 604 ‘Yellow Book’ (stock) Rebuilt Engines will require the following:

1.    All 604 Engines will use the Allstar Performance Adjustable ½ Inch Base Plate Part # ALL26180. Link: https://allstarperformance.com/adjustable-base-plate-1-2in-all26180/

1. All 604 Engines will use the Allstar Performance .950” restrictors – Base Plate Insert .950 4pk for 1/2in Spacer Part # ALL26181

Link: https://allstarperformance.com/base-plate-insert-950-4pk-for-1-2in-spacer-all26181/

1. 6000 maximum rpm with proper chip or dial settings.
2. Factory sealed 604 will carry 30lbs. over the 602 cars.
3. Yellow Book rebuilt 604 will carry 50lbs. over the 602 cars.

Repeat: All 604s used, must be “GM 604 Factory Sealed’, or ‘GM 604 ‘Yellow Book’ (stock) Rebuilt’ with the All-Star Performance .950 restrictors.

In 2021, Kern County Raceway plans to utilize Factory Sealed 602 Engines only.

KERN COUNTY RACEWAY PRO LATE MODEL SCHEDULE and WINNER’S PAYOUTS:

The April 18^th Pro Late Model race will pay $2,500 to win, the May 2nd Pro Late Model race will pay $2,500 to win, the June 20^th Pro Late Model race will pay $4,000 to win and the September 5^th race will pay $4,000 to win.