GM 604 Motors will be allowed to be bored .20 over. Certified engine builder must use UCRA “+.20 seals” following engine work. Engine must completely conform to UCRA specifications, and use determined pistons and parts. Car will also have to add 50 lbs. to total weight.

Fuel can be protested. Any top 5 feature finisher may protest any top 5 competitor. Protest fee is $100 (20% to SMS). Percentage (ethanol to gasoline) will be checked. Must check 85 +/- (2). Tolerance will be 83-87 only. Fuel must be clear. (No red, purple, green, etc.) If determined illegal by SMS officials, the car/driver will be disqualified from the event.

Car bodies are allowed 72” deck width Car bodies are allowed 37” deck height (+/- 1” tolerance)

ONE Shock per wheel; may run dummy shock or chain on left rear

All Four Bars must be Solid Rods with Heim Joints on each end

Engines must meet GM factory specs and rebuilt engines must meet GM rebuild specs

Must have all GM parts

Assemble height on GM 604 engine can be no less than 1.780″

Must have GM 604 stock valve springs

All engines must have factory GM sealing bolts, any Crate Sanction Seal System Allowed

No Black Market Seals, Any other Seal System call for Approval

604 Engine 1″ max Carburetor Spacer

602 Engine 2″ max Carburetor Spacer

No Tri-Y Headers

Mufflers may be required at certain tracks

Engine placement 7″ from center of Ball Joint to #1 Spark plug

12″ Spoiler and Sides Max

Racing Gas or E85 Only



Front Open

Rear Hoosier 1600 or Equivalent, American Racer 56 or Equivalent

All Rear Tires must Punch 55

Sipe and Grooving Allowed

No Grinding off of numbers or compound

Any Tire that has been altered will be illegal and confiscated

All tires will be checked with a durometer

No Chemical treating of tires allowed

All tires subject to sampling at any time

The Top 5 finishers in each Feature will report to tech immediately after the race

All Engines are subject to impound and teardown by The SMS


809 Brick Mill RD
Maryville, TN 37801