[Dwight Southerland]

Other ideas:

1) Maximum 150 lbs. valve spring pressure on the seat. Maximum 1.500 valve spring diameter. Dual springs w/damper maximum.
2) No external modifications to intake manifolds.
3) Limited to untouched factory intake manifold or aftermarket dual plane.
4) Roller rocker arms allowed, no stud girdles. Original rocker arm mounting configuration.
5) Deep oil pans (none below the lowest frame crossmember), no kickouts.
6) No port plates on headers.
7) Original OEM crankshafts or approved aftermarket only; no custom aftermarket billet strokers.
8) Three speed automatics and four speed manuals only, regardless of OEM configuration.
9) Steel valves only.
10) Rear wheel wells may be modified internally for maximum legal tires.