I too, am guessing Cyclone 1-5/8". I helped put a set of those on my buddies 66 Barracuda in 1974. As I recall they were awful expensive....right at a hundred bucks!!
I paid $60 for mine. Still have them too! Trying to decide whether to use them or patch the holes & get a set of Doug's.
Mopar Boy. Looking at that pic of the collector area that could easily be the same thing I have. I thought mine exited just a bit further back but I'm probably wrong. Back when I put them on I was lucky enough to find some 2 1/2" 45 degree bends with a 3" collector reducer on one end. They were perfect for dipping under that little bit of frame extension (or whatever it is) & turning the exhaust toward the center of the car. Added another set of 45 degree pipes & it headed to the back of the car.