I think Cyclone headers had the separate flange for the ports, like those in the picture, instead of one continuous flange. Maybe Blackjack was like that too. Been too long since i have seen either of those. I think Cyclone and Blackjack were 1 3/4 though.
Yes....Blackjacks were also like that with the slip collector plate. I had 2” blackjack alumacoat headers on my charger when i got it 34 years ago. But don’t have any good pics of them. So i don’t remember if those could be blackjacks. But, i don’t remember having that slip connector bolt plate (not sure of name....hahaha).
