The NHRA Technical Department has released a rules change affecting the combustion chamber of Super Stock cylinder heads. This amendment to the 2004 NHRA Rulebook is effective immediately. In the Super Stock section under CYLINDER HEADS on page 68, the rule will now read:

"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. Valve guide centerlines must maintain the stock lateral and front-to-back location as machined by the OEM. Valves must maintain stock angle. Cylinder head must be able to hold combustion chamber, intake and exhaust runner volumes per NHRA Specifications."

In commenting on the change, Len Imbrogno, NHRA Director of Member Tracks and Sportsman Racing stated: "This rule change is intended to enhance NHRA's ability to inspect and enforce rules for all cylinder heads. Because the new rule is easier to verify by objective means, we expect to reduce the possibility of inconsistent results."