I'm sure I'm missing some obvious answer but what options does someone have to run a car that is not listed in the NHRA stock eliminator weight/hp breakdown sheet? If someone wanted to run a non-drag Pak Challenger or charger, would it fit/be permitted in an existent class?

What about a V6 charger? Gen 3 Hemi swapped 70s car (this one may be an obvious SOL but I keep thinking about the v8 rwd cobalts)

Sorry if these are dumb ? but the US Nationals had me curious.