Quick... which way's better (225/273)

If the goal was 175-250 hp and didn't mind spending good money to get there and really liked the idea of running a /6 then I could see picking /6. Turbo is an option but I've seen a few who had problems getting them to work, depends on the OP's skills. But if wanted the least hassle way go, V8, 360 probably be best to 273 least, a running 5.2/5.9L magnum basically make 300 hp with 4bbl and headers add cam for another 25-50+ hp.