Sump: If a vehicle originally had a wet sump lubrication system, the sump may be modified to ensure a constant source of engine lubrication at the oil pickup tube. This does not allow conversion to a dry sump system.
The addition of any oil cooler, oil filter or Accusump-type system is allowed.
Internal engine parts may be balanced.
Any chain tensioners or guards are allowed.
Interior Modifications - Alternate seats may be used.
Roll bars: Upholstery may be removed to accommodate weld-in roll bar mounts.
Gear Shift Linkages: Gear shift linkages may be modified or exchanged.
Seam Reinforcement: Use of reinforcement kits, addition of plates to reinforce seams or suspension control arms, and welding of seams is permitted.
Inside fender lips may be rolled or ground to prevent tires from rubbing. Fenders (including wheel openings) may be modified provided the tire-rim-spacer combination and ride-height setting used could be used without the fender modification (i.e., could be used on an unmodified vehicle of the same model) with no penalty points.
Squirting water into the air flow generated by an engine's cooling fan to assist in engine cooling is permitted.
Any fuel pressure regulator may be added to any vehicle originally carbureted as a free modification, and may be added to a vehicle converted to carburetors with no additional points other than assessed for the carburetor conversion.
In Improved classes, the factory X50, X51, X53 and Sport Chrono options are allowed as free modifications.
Generally, there are no weight specifications applicable to Street, Production, or Improved classes. However, vehicles in these classes may not be lightened except as a direct result of permitted modifications as listed in this Chapter IV. But if a vehicle has been altered to be in a model range other than its model range of manufacture, then it must meet the weight minimum specified in Appendix B regardless of permitted modifications.
RMR/AMR Event Rules – 2008Page 15