Well it's not just slightly different stroke, there is a fair capacity increase. By your logic of an engine just explodes fuel and air and thats all that matters, comp ratio , cam shafts, porting etc all don't matter either. There are many factors that determine an engines pwr delivery characteristics and people's goals vary. I know I want more torque, along with decent power. An example would be hypergears latest turbo making 490kw, but with a close to verticql line at 450orpm. That engine might be fun to drive for a bit, but would very quickly become annoying. More capacity and different cams would turn it into an absolute beast. The op said budget want an issue, which translates into fitment issues aren't a problem. He should just buy a rips engine and be done with it!