Limited Mod (Small Block) Rules
Updated: Jan 19
Maximum weight 5200# Hitch Height 20”
1. Tractor weight class will be 5200 lbs.
2. A maximum tire size will be 20.8x38, radial or bias ply, cut or uncut.
3. Tractor must be 1963 model or older. No homemade tractors. Any model sheet metal can be used.
4. Any pump gasoline or racing gasoline is allowed. No alcohol or nitro methane allowed. Oxygenated gasoline (Q-16 or similar) is allowed.
5. Stock rear-ends and tinwork is required.
6. Must have tractor appearing front-end. No tricycle front-ends. Front tires must be in driver’s line of sight. The front-end must be at least 36 inches from center of tread to center of tread on front tires.
7. Total length of tractor must not exceed 11 feet from the center of rear axle to the furthest point forward, including weights.
8. Tractor frames can be modified or custom built but must retain stock length wheel base +/- 4 inches.
9. Engine must be an automotive type V8, 410 cubic inches or smaller. Must be a small block, no big blocks, no Hemi, no Ford FE.
10. Must be a cast iron block with cast iron heads. Two valves, one spark plug per cylinder. Camshaft in block.
11. A maximum of (1) 4 barrel, 750 cfm carburetor, must be stock out of the box. No flowed carburetors, no fuel injection, no throttle based injection. Must have Holley list number on choke horn #4779.
12. Factory style distributor. No crank-trigger ignition.
13. Aluminum intakes allowed.
14. Tractor must be equipped with an SFI approved clutch and pressure plate, SFI approved flywheel, and SFI approved bell housing. Tractors must also have either a block saver plate or rear motor plate between the bell housing and engine block. Automatics will have a SFI blanket on Trans and over flywheel.
15. No shifting of manual transmissions or T.A.’s during pull. Automatics are allowed to shift.