Worth the trouble?

I like those cams.

IMO, yes, install new pistons. The ones mentioned or KB-107's and have the block milled if need be for a zero deck height on the pistons. Use the mentioned cam(s) above to suite the driving needs. (Smaller one is a great choice.)

Keep everything else. The intake is large enuff. A swap would only make me install a RPm for better drivabilty and torque. Everything else stays the same.

I think the 440 swap a cool idea, but a expensive one. And for a street cruiser...honestly, I really do not see the point have having both like set ups.