"K" Members

Going from a slant 6 to a small block in a 1967 barracuda, what year K member would be needed? Also, I would be removing the p/s and I don't remember what gear box was used to replace it. Car is rust free and has a/c but is a 6 cylinder car. Is doing a V/8 swap worth the money, effort? Asking price is 16k obo? I have people that are willing to help me with the swap. What do the K member bolts get torque too? I figured that removing the p/s would make the driver side header easier to put on. It's a notchback and I think that they are a cool body style. I know that I said I would avoid the earlier barracuda's, but it's clean. Can a 904 transmission be used with a mild built 360? I figured that since I'd be going to a V/8 why not a 360.