magnums & A bodies exhaust fun(not)
Those ports look like ones I've seen on W-8 or W-9 heads.
MP makes special kit to adapt them to the standard header flanges, IIRC.
Or maybe it was that MP sold the flanges to weld to the headers?
I forget.
I'll bet you thought you were getting a helluva deal on some cheap aluminum heads at some meet and they were likely MP closeouts that you'll have a hard time finding replacement parts for, much less accessories like headers.
Mark.