cam swap

ok, here it goes,
if i take an '81 csr kz650 motor which is set up factory with the hi-vo timing chain, and a set of cams from an '82 kz750 ltd, Is it a straight forward swap? Both cams have the same base circle , if i remember it wasnt until '83 that the 750 cams went to the smaller circle, and even then that should be able to be corrected with shims, right? just checking that i do this right. Do i set the timing gears to the 750's timing position or the 650's timing position? I see they use the same gear.
Will the 650 springs be sufficient or do i need to upgrade ? The cams im looking at also have the machanical tach drive and it looks like that should line up well.
it's maybe a differance of what? about .025" in lift and maybe 10 to 15 degrees of duration? if i use adjustable timing gears or slot a set of stockers can i get more bottom and mid out of it by advancing approx. 4 degrees like i can with automotive cams?
This engine sees alot of dirt and hill climb action and i plan on taking to the strip to play a bit here and there.It's also a blast on the highway when it snows ,lol.