The 318 NON believers

Super Stock Engine Rules per NHRA rule book

CAMSHAFT
Any camshaft and valvetrain permitted.

CYLINDER HEADS
Must be correct casting number for year and horsepower claimed,
per NHRA Technical Bulletins or NHRA-accepted. Cylinder-head
casting must also be on NHRA runner volume list as published in
National DRAGSTER and on NHRA.com. Porting, polishing,
welding, epoxying, and acid-porting permitted. Grinding and
polishing in combustion chamber permitted. Welding and/or
applying epoxy in combustion chamber prohibited. Spark-plug hole
must maintain the stock location, size, and angle as machined by
the OEM; spark-plug adapters prohibited. Valve-guide centerlines
must maintain the stock lateral and front-to-back location as
machined by the OEM. Valves must maintain stock angle; valvestem
angle must remain stock, +/- 1 degree. Cylinder head must be
able to hold combustion chamber, intake and exhaust runner
volumes per NHRA Specifications. Any aftermarket steel valve
permitted; must maintain stock head and stem size; titanium valves
prohibited. (OEM sodium-filled valve may be replaced with titanium,
provided weight is equal to or greater than original.) Valve diameter
permitted to be +.005-inch or -.015-inch from published NHRA
Technical Bulletins. External modifications prohibited. Welding or
epoxying permitted on external portion of runners for repair only,
maximum 2 runners per head. Heat riser passages may be blocked
off from intake-manifold side of cylinder head or in exhaust port.
The following are permitted: polylocks, jam nuts, screw-in or pinned
studs. Any valve job accepted. Exhaust plate permitted between
header and cylinder head, maximum 1/2-inch; may not protrude into exhaust port. Cylinder head may have all seats replaced.