My local commercial track runs a class called "Spec Womp" and I haven't had a chance to ask if this is just a local class or if this is a regional class - so I thought I would throw the question out here. Here are are the requirements / restrictions noted in the rules for the class:
Parma Womp Chassis
Plafit Rabbit motor with 9T pinion (spur gear count not restricted)
spec rear tire #699 13/16"
stock guide flag #645
maximum width of car 2 1/2"
.050" min clearance front and rear at all times during race
weight can be added to improve handling
The races are run the King track at the local speedway and the racing is typically really close and pretty entertaining as it is kind of like a box stock class.
Will be curious to hear if this is a "formal" class and if so, what others think of it.