1974 NASCAR International Stock Car Racing Rule Book Modified Division Section 20C-2 -- Engine

No overhead cam engines permitted.

In 1974 the Modified Division competition will compete with two minimum weights for engines designated as: BIG block engines and SMALL block engines.

BIG blocks must maintain a minimum weight of no less than 2,850 pounds with gas, oil, and water (without driver). Cars weighing less than 2,850 pounds with gas, oil, and water (without driver) not eligible.

SMALL blocks must maintain a minimum weight of no less than 2,600 pounds with gas, oil, and water (without driver). Cars weighing less than 2,600 pounds with gas, oil, and water (without driver) not eligible.

Listed below are the basic engines designated and approved as SMALL block engines. Any engine not listed will be designated as a BIG block engine:

NOTE: The 400 cubic inch General Motors engine having 3 freeze plugs is designated as a BIG block engine. The similarly appearing G. M. 350 cubic inch engine has only 2 freeze plugs and is designated as a SMALL block engine.

a. Displacement may be changed to any size. NO ALUMINUM BLOCKS PERMITTED.

b. Piston displacement is unlimited. Engines may be interchanged in any manufacturer's line providing car meets all other specifications.

c. Motor may be moved in chassis on all cars, providing the steel fire wall separates the driver's compartment from the engine.

d. No overhead valve conversions permitted on stock L-head engines.

e. Any type camshaft, valves, valve springs, pistons and connecting rods allowed.

f. Fan and fan belt may be removed.

g. Any type water pump permitted.