exhaust woes ......1973 340 into a 1965 barracuda
dougs and tti make headers. not cheap but an option..
find early abody 273 manifolds.. they will need the slightest work to fit. not ideal but they will work and fit the best. probably choke it some too but it is what it is.. i ran them on a 360 in a 64 valiant.
the later 340 manifolds will work. 73 style.. they are tight but work. friend had them on his 66 barracuda. may have to slightly lift the motor to bolt them on