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1. All chassis rules that apply in the National 4x4 class will be the same. (NTPA RULES)

Engine Limitations

1. Must be a wedge head.
2. No “Twisted Wedge” or special canted valve heads will be allowed. 
3. Heads must be of the type that is readily available to the public. (Can be bought from Jegs, Summit, etc.)
4. No DRCE Heads allowed.
5. No one-off specialty heads allowed of any kind.
6. Must be stock bore space of engine manufacturing 1.840 (Chevy), 4.900 (Ford), 4.800 (Chryslerr).
7. Engine Block and Cylinder heads must be in cast form. Steel or Aluminum. No Billet Blocks or heads.
8. 650 Cubic Inch Limit with 1% Allowance.
9. Max Cam Lift of .950 at the valve (was voted on to keep this a rule for 2023)
10. Chevy engine will be limited to nothing less than a 12 degree valve angle.
11. Engines subject to be pumped at any event.