[Mike Carr]

Box allows Delay Boxes. No-Box does not allow delay boxes. Different classes go by different names at different tracks. ET 1, Super Pro, Electronics, Box are usually the same. Pro, No-Box, ET 2, Modified same thing. Most tracks (but not all IHRA Pro-Ams) offer Street ET also. Most classes have a maximum ET that you can dial-in. Box might be no slower than 11.99, No-Box might be no slower than, say, 13.99 or 14.99. Street ET is usually no ET limit, though some I have seen are now slower than 17.49, or 19.99.