1974 NASCAR International Stock Car Racing Rule Book Modified Division Section 20C-21 -- Glass

a. Headlights must be removed. Headlight holes must be covered with sheet metal.

b. A safety glass windshield is compulsory on the driver's side with a complete windshield screen on the right side. It is permissible to use a minimum 1/4" thickness plexiglass[sic] 10" x 15" mounted inside a metal frame inside the car in front of the driver. When using this type of windshield installation maximum 1/2" square wire mesh must be installed in the normal windshield location. The screen can be omitted if full windshield is used.

c. Rear view mirrors optional on tracks of less than one mile. Rear view mirror cannot extend outside of car.

d. All side window glass must be removed. All Modified cars competing in NASCAR competition at all tracks will be required to use a NASCAR-approved nylon mesh screen in the left side driver's window opening. (See diagram in rear of Rule Book for proper installation).

ATTENTION--REAR WINDOW MUST BE COVERED WHEN REFUELING DURING RACE.

e. RULE VARIATIONS FOR SUPER-SPEEDWAYS AND ROAD COURSES.

(1) Full windshield in good condition compulsory.

(2) Plastic glass may be used in lieu of original glass but must be same thickness as original windshield glass.

(3) Windshield and rear glass must be installed in their original standard positions.

(4) Chrome trim or moldings must be pop-riveted and/or bolted in a safe and workmanlike manner. Windshield safety clips 3" x 1" x 1/8" must be installed. Three clips bolted to top of car not pop-riveted extending over the edge of windshield. Two clips will be bolted to the cowl and extended over bottom edge of windshield. Bottom clips must be visible. Clips must be evenly spaced a minimum of 12" apart.

(5) Rear window is recommended and when rear window is used it must be permanently closed. Plastic glass when used in lieu of the original rear window glass, plastic glass must be same thickness as the original rear window and must be secured with two steel straps not less than 1/8" x 1" bolted to roof panel with 5/16" bolts.