Headers for 67 barracuda 318 with no modifications

Hello Mopar friends, I’m wondering what headers will fit on a 67 barracuda with a 318 with no modifications, I was told Doug headers would & are there different ones for 273,340&360? I’m still kinda new to all the differences and imagine different heads would probably use different headers, thanks for helping me learn this stuff in advance!
Why? A lot of expense and work for no benefit.