65 barracuda

at least you're looking at fitting a 383 not a 440. i put a 440 in a 65 dart and headers were real tight, but a 383 should be ok.
neil.
I had a 67 dart several years ago that the previous owner put a 383 in. Of course it was a manual steering and brake car so it didn’t have those taking up room,and it had reg exhaust manifold.