6200 National Sportsman 4x4 Rules
- All chassis rules that apply in the National Fwd class will be the same. ( NTPA rules )
- Must be a wedge head
- Valve angle on heads will be limited to nothing less than 12 degrees
- No "Twisted Wedge" or special canted valve heads will be allowed.
- Heads must be of the type that is readily available to the public. ( Can be bought from Jegs Summit etc.)
- No one off specialty heads allowed of any kind.
- Must be stock bore space of engine manf. 4.840- Chev / 4.900 Ford / 4.800 Chrysler
- Engine Block, Cylinder heads must be in the cast form. Steel or Aluminum. No Billet Blocks or heads
- Max Cam lift of .950 at the valve
- 650 Cubic inch limit with 1% allowance