School me on NHRA drag racing classes...

As my Duster gets closer to being fit enough for racing I am wondering if I could get involved in amateur drag racing at my local drag strip (Bandimere Speedway in Morrison, CO). I am pretty clueless on classes and such and I don't know what my car would fall under. I would also rather not do bracket racing as it doesn't seem like the kind of competition I would have fun with but from what I've seen it seems like slower street-rod type builds like mine don't have any other options. My car is a '70 Duster with a 360 I built myself which replaced the original 318, it weighs around 3300 lbs. with driver and half-tank of gas. I took it to a test & tune night and ran a best of 15.3 @ 93 ET and that was with crappy bald rear tires and stock 7 1/4" rear with 2.76 gears, I think it could hit low 14's at this elevation with the correct chassis/rear end setup and some tuning.