1974 NASCAR International Stock Car Racing Rule Book Grand American Cars Section 20A-7 -- Wheels

a. Wheels must be reinforced and/or approved by NASCAR Technical Director. General appearance must not be changed. Only steel wheels permitted.

b. All four wheels must be same size and diameter at all times. Grand National type wheels must be used.

Fourteen or fifteen inch diameter wheels permitted. Maximum rim width 8 1/2".

NOTE: For AeroWarriors.com users, Grand American Cars are governed by the same rules as the NASCAR Grand National Championship Division, with the exception of this Section, and the following:
Section 20A-1 -- Competing Models
Section 20A-2 -- Engine
Section 20A-3 -- Engine Mounts
Section 20A-4 -- Minimum Weight
Section 20A-5 -- Frames
Section 20A-6 -- Ground Clearance