CB550K Build - CB650 Motor Swap vs Cam Swap

Just wanted to know is it really worth swapping a cb650 cam into a cb550 motor? Or would I be better off swapping an entire cb650 motor/exhaust/electrical etc? Im just curious as what gains I would see from one or the other.

The bike is a 77' cb550k, and I just picked up a complete 81 cb650c w/ a 4-1 exhaust.

the 650 cam in a 550 is a marginal gain, similar to that of a light street profile cam.....guys do it cause you can usually find a used cam around $100 with the tach gear necessary to get it working....

with that said, everything about the cb650 motor is better. The chamber design is lightyears ahead, it flows so much better, valves are almost 20% larger, obviously there's 100cc more displacement, the clutch is better, etc.

if your 650 motor is in good running condition, you will be pretty pleased with it in the 550 chassis. to get it in though, you have to remove the oil filter housing, the oil pan, and the oil pickup funnel on the bottom, as the 650 frame has a removable section on the lower left so the pan can fit during install/removal.

Curious to know what you did