Engine options are new for three more IMCA divisions beginning in 2011.

Stock Car drivers will have their choice of running an unlimited cubic inch engine with a 350 cfm Holley carburetor or a newly-added limited cubic inch engine with a 500 cfm Holley carburetor, while Hobby Stock and Southern SportMod drivers can compete with a GM 602 crate engine or a claim engine.

All options are included in rules for next season, already posted on the IMCA website and published in this month’s newsletter.

Rev limiter chips will be required for Modifieds (7,800 rpm) and Late Models (8,000 rpm). IMCA has also reserved the right to require a chip in the Stock Car class if warranted.

Lift bar or fifth arm rear suspensions will be prohibited in Modifieds as of June 1, 2011. After that date, drivers must run a pull bar style rear suspension.

“Rear suspension is the driving force for engine costs,” said IMCA Vice President of Operations Brett Root. “We are not going to allow chassis manufacturers to drive the market and jeopardize the livelihood of this division. We can’t have products like rear suspension go unchecked.”

Next season will also be the last for use of titanium valve retainers in Modifieds.

No shaft or pedestal rocker arms, and no titanium components will be allowed on the 350 cfm carburetor Stock Car engine.

An OEM two barrel remains the required carburetor for use with any Hobby Stock claim engine while a GM Rochester and carburetor adaptor are required for use with the crate engine.

The part number for the adaptor will be announced on or before Dec. 1. Oil pan clearance issues in the class will be determined by the same date.

Hobby Stock drivers will also have the choice of OEM or aftermarket front bumpers.

Karl Chevrolet Northern SportMod drivers with claim engines will be required to compete with Holley 4412 or Holley HP version carburetors.

Use of the Rochester two barrel will no longer be permitted, as was announced earlier this year.

Southern SportMod shock rules for 2011 specify the use of one steel non-adjustable shock per wheel. One or all shocks may be claimed for $50 each.

One of two specified Dynatech headers may be used, in addition to the Schoenfeld headers already in the rules.

In addition to structural issues, the biggest change for the Mach-1 Sport Compacts is in claim procedures.

Claimed drivers will have their choice of $1,500 in cash or $500 in cash and exchange on the complete car. Their previous options were the $1,500 or the straight exchange.

Procedures for other IMCA divisions with the claim rule will be announced in December.

Car numbers in all divisions must be a minimum of four inches wide, 20 inches tall and clearly visible on both sides and on the roof.

The use of RACEceivers will be recommended, but not required, for all divisions at all sanctioned events in 2011.

Drivers will also have their choice of Snell rated SA2000, SA2005 and now SA2010 helmets next season.

Rules will be mailed to drivers purchasing 2011 competitor’s licenses and included in tech inspector manuals sent to sanctioned tracks.