These are the dimensions I used in the past. In case somebody whats to make that shim.
I had plenty of the early servos, including from '77-'78 truck transmissions; so I never ran the shimmed later servo.

Front_servo_shim2.jpg
1993 Daytona, 5.50 at 130mph (1/8) 1.19 sixty ft (PG). Link to 572 B1 - Part 1