2013 Thunder/Lighting Rules
- 1970 – 2012 models allowed
- Steel, aluminum or fiberglass bodies allowed. No wedge bodies allowed
- Bodies must retain stock appearance
- Ten (10) inch spoiler with matching sides
- Two outer sides, max 24 inches long
- Make of car and engine brand doesn’t have to match
- Minimum tubing size 1-1/2 inch, .083 minimum thickness
- Steel OEM Block only
- Chevy : 362
- Ford : 364
- Mopar : 372
- Flat top pistons, zero deck, plus or minus .003 tolerance
- Crank (stock stroke) for engine claimed minimum 49.5lbs with key, gear, and pilot bushings.
- Any Steel Rod allowed.
- Wet sump oil system only.
- Any Steel with standard 11/32 valve stem
- Chevy 23 Degree: 2.020 Intake 1.600 Exhaust
- Ford 351 Head: 2.020 Intake 1.600 Exhaust
- Ford 351C Head: 2.19 Intake 1.71 Exhaust
- Mopar W2: 2.020 Intake 1.600 Exhaust
- No CNC porting or polishing
- 200cc casted head max port rule, no porting: cannot measure over 210cc ( no tolerance)
- Head can be ported if casted under 200cc,cannot measure over 210cc ( no tolerance)
- Angle milling allowed
- No Titanium valves
- Any Valve springs
- Roller rockers allowed, NO SHAFT ROCKERS
- Any Flat Tappet cam. No Mushrooms
- Lifter Diameter must be OEM size for make
- Any cast one piece aluminum
- One four barrel carburetor
- Must have any stock OEM front chassis.
- Stock lower control arms
- Tubular upper control arms allowed
- Stock type steering box and drag link eliminator.
- Leaf or 3-link rear suspension only
- 103” inch wheelbase minimum, plus or minus ½ inch tolerance.
- Coil overs allowed on rear only. No moving birdcages.
- Racing shocks and wedge bolts allowed. No adjustable or Gas charged shocks allowed.
- #1 spark plug MUST be in line with upper ball joint. One Inch Tolerance
- Can be tubed from Driver back.
- Cars Tubed from Mid-plate back, must carry 5% weight penalty.
- Stock type or Quick-change
- Wide 5 hubs allowed
- No rear independent suspension allowed
- Ni Lift bars
- Recommended anti-rollover chain or device
- Must use Safety Bell housing.
- Triple disc clutch OK
- Automatics allowed
- Bert/Brinns allowed
- Right Rear tire must punch 50 or more at any time.
- Max 363 Cubic Inch with any wheel : #2750
- Max 363 Cubic Inch with 10 “ or less wheel : #2700
- 604 Crate : Any Wheel : #2500
- 602 Crate : Any Wheel : #2400