Not much, and carb allows more tunability and power potential with less. It all depends on how much you're willing to do. Ported head, bigger valves, better cam profile, head with proper exhuast. All will net you decent gains, but it is all kinda pissing in the wind. If you're considering efi, strongly consider spending the extra up front and just swap in a 3rz. And this is from a guy who's tired of hearing of 3rz swaps
