The standard 750 carb swap has been a common and good running swap for ever. Keep in mind you will lose the vacuum actuator that bumps up the idle when you drop it into gear but its not a huge deal, may just have to bump the idle a tad or maybe modify it to fit if your good with building brackets. Most use the earlier roundtop carbs as they are proven and easy to tune and makes a noticeable difference by themselves, you will need pre 77 K carb boots, cant remember if the air box side fits or not. but if you add a stock K or F cam or better yet a DP295 cam it will really wake it up. The auto really respond well to motor mods, 836cc pistons, roundtop carbs, cam swap and clean up the stock intake ports and it would be a fun little ride.