65 barracuda exhaust

I'm about to swap a 318 in my '65 Barracuda that currently has a slant 6. The guy I bought the engine from offered me the dual exhaust from his '68 Dart convertible for cheap as well. I thought it had to be modified too much, but if you are saying that at least from the trans cross member back it fits, then that might make sense for me to just take it to an exhaust shop and get new pipes from the stock '65 manifolds to the cross member.
OK, but remember the Dart has a 3 inch longer wheelbase than the Duster whose exhaust pipes I used. I would guess that you could simply trim three inches from the Dart exhaust pipes and they would work, but I have not tried that, so cannot guarantee it. The 68 Dart tailpipes should be fine as is.