340 vs. 360 build?

Hey guys I am new to the site and have been researching this since before I even joined. I have a 73' Duster w/ the 318/727 combo. I am wanting to build it up for street/strip performance nothing super crazy like no big block swaps or anything. I am expecting to have to rebuild whatever motor I get though and will be upgrading to some more performance oriented parts.

I can get a 360 from this guy for $200 right now but I am still looking for a good deal on a 340 six pak (hard to find). I would rather put more money into upgrading parts than just buying a motor. Also would I have any problems w/ either of those motors bolting up to the 727 tranny?
I am looking to get the car into the 12's or better. I plan on a 410 gear, locker, ratchet shifter, upgrading fuel system, spark system, intake, carbs, possibly new heads or at least rebuilt, and internals, possibly stroker kit. Is it possible to drop a six pak onto a 360 or what would the best carb/intake option be for the 360?
Thanks everyone for your opinions and hopefully I can get pointed in the right direction.