Raceivers are mandatory in all classes, the channel is 454.
There is a muffler rule for IMCA Stock Cars, Sprint Cars & both classes of Modifieds. The Schoenfeld IMCA 609 Muffler or 4 inch muffler insert #43035, #42530 or Schoenfel Shorty mufflers 80305, 83535, 63535, 103535K All must remain unaltered.
