Please help me make these fit!!!

I plan on following the Stock or Super/Stock class rules in NHRA so either way is acceptable I believe. I think I am going to take both and my buddy who is helping my build it said he will be looking for a set of headers ( he likes TTI) for his nephews duster. So either way I am covered. Just like to hear what everyone else has to say.

68 Valiant400; do you have any figures to back up the differences?

Thanks,
Gary