Welcome Cap'n, loved the work you did in your movie!!! ;-) I just read a post about putting later headers into an early A body, so look for that thread! It can be done, but cutting a tabbing is involved! If I can find the link I'll post it here!!
I thought about trying to make some shorty headers for it like the ones that come on the late model SRT Challengers. 30 yrs ago I was one heck of a welder. I'm a little rusty these days but getting better.