I've used both sizes of the BB Hooker A body headers and one size of the Hedmans in many different A body BB Mopars, I liked the Hedmans the best
I have a slightly used set of older Pro Part 2.0 primarys that I had one pipe(#7) modded a little to fit in my H code 1969 Dart GTS, I ran them about 30 miles and thenput some stock manifolds on it. Those headers where designed for 440 blocks in A bodies, not low decks
They are available and for sale
PM me, anybody, if interested