1976 NASCAR International Stock Car Racing Rule Book NASCAR Grand National ® Championship Division Section 20-2 -- Engine Eligibility

a. See Rule 1-C.

b. Engine may be located so center line of #1 spark plug hole on short side of engine block is in line with the upper ball joint except on Monte Carlo Chevrolet. When using the small block engine -- engine must mount in standard location. However, this is the maximum allowable backward position of engine.

c. ENGINE MOUNTS

(1) Motor mounts must be reinforced.

(2) Only NASCAR approved reinforced motor mounts can be used.

(3) All motor mounts must be securely bolted.

(4) Engine may not be moved forward or aft from original position (See 2.b).

d. ENGINE DISPLACEMENT: Bore and stroke may be changed provided the total displacement does not exceed maximum displacement for a specified class. Small block engine up to 358 cubic inch displacement. Big block engine 358.001 to 433 cubic inch displacement.

To clarify the identification of "small block" engines, listed below are the basic engines designated and approved as "small block" engines. Any engine not listed will be designated as a "large block" engine:

*Cubic inches must be reduced to maximum 358 cu. in. by reduction of bore and/or stroke.

e. CYLINDER BLOCKS: Must be production with standard external measurements in all respects with the exception of the permissable overbore.

f. Pistons optional.

g. Internal polishing, porting, altering and/or relieving of motor parts permitted.

h. Maximum to valves per cylinder.

i. Oversize oil pans and oil coolers are not to be used unless approved by NASCAR. Oil pans must have a minimum ground clearance as specified under inspection procedures.

j. CYLINDER HEAD: Must be an automobile manufacturer's original casting with no external modifications. Must be NASCAR approved. No aluminum heads permitted on engines with less than 358.001 cubic inch displacement.

k. Internal changes permitted.

l. A cylinder head is considered to be a "Standard Production" head if:

(1) It is the required cylinder head for a previously approved complete engine, said engine being available as an optional engine for a regular factory product offering. If previous head useage is questioned by NASCAR before approval is granted, the competitor must furnish documentation of prior usage.

(2) It does not change combustion chamber, type of valve action (Push Rod) or number of valves, used in the cylinder head assembly of the approved engine.

m. Crankshaft -- Standard production design. Stroke may be increased or decreased. Balancing permitted.

n. Camshaft optional.

(1) Camshaft must be driven the same as approved production engine. Gear drive not allowed unless approved standard production.

(2) Solid or hydraulic valve lifters optional. Roller tappets not allowed unless standard on volume production engines.

(3) Rocker Arms -- Any rocker arm standard on approved engine being used and NASCAR approved roller bearing rocker arms.

(4) Rocker arm supports must be standard production in design and size.