1976 NASCAR International Stock Car Racing Rule Book NASCAR Grand National ® Championship Division Section 20-4 -- Carburetor

a. Carburetor must be NASCAR approved. Approval of carburetor shall mean approval for all competitors and cost of carburetor shall be a factor of consideration for approval. No external alterations permitted.

Carburetors for Small Block Engines up to 350.000 C.I.

America's greatest auto race drivers competing with the finest equipment developed by America's automotive manufacturers.

Holley 4150 series carburetor P/N 7785 with 1 1/16 venturi and 1 7/16 throttle bore size. Additional rework will be permitted, such as removing choke horn and deburring venturi and boosters. The venturi must remain 1 1/16 (1.0625) maximum size and the throttle bore must remain 1 7/16 (1.4375) maximum size. All modifications must be approved by NASCAR.

Holley 4500 series carburetor P/N R4575, R6464, R6605 only may be used. No external alterations permitted. The NASCAR approved 4500 series carburetor has a 2-inch throttle bore and butterfly and must be sleeved to a 1 5/16 (1.3125) base opening. The only permissible alteration is the change in the base opening size. Absolutely no throttle bore reduction in size permitted above the base insert sleeve. Throttle bore must remain 2 inches.

Intake manifolds must remain the same as previously approved. Absolutely no reduction in intake manifold openings.

Carburetors for Engines 350.001 to 433 C.I.

Holley 4150 series carburetor P/N 7129 with 1 1/16 venturi and 1 7/16 throttle base opening to be used with a NASCAR flat restrictor plate with a maximum 1-inch opening. No additional rework allowed on this carburetor.

b. Carburetor spacer not to exceed 1 inch in thickness may be installed on manifold. Only 2 paper gaskets (1 per side) maximum thickness .050 will be permitted.

c. Gaskets can only be altered to match carburetor base openings.

d. Fuel injection or superchargers not permitted.

e. Jets may be any size.

f. Carburetor restrictor must be used when required by NASCAR.

g. Heat risers may be blocked.

h. Any NASCAR approved gasoline filters may be used.