Headers for a 70' Dart Swinger

I have a 70' Dart with a 383 engine in it. I want to get some headers for it but I cant find anything for that engine that is made to fit the car. Obviously since in 1970 they didnt make a production Dart with a 383 option. I dont really want to resort to fenderwell headers if I dont have to. My question is this... Would headers made for a 383 in a 69' dart fit my 70'? Or are the under carriages and body frame different? For example these headers? http://www.summitracing.com/parts/SUM-G9141/?rtype=10 Has anyone tried something like this?