iv been meaning to change my drive shaft seal fore some time now and finaly got round to it.... turns out i have a much bigger problem than just a oil leak.....

http://imgur.com/a/cXDgt

it seems my whiring noise in 6th is actualy the 6th gear moving on the shaft about 20 degrees... and my counter balance bearings are fried and my crank bearings arnt far behind, never mind second gear thats completly destroyed.......
belive it or not this bike still ran perfectly and had no issues with running or gears except for the slight whine in 6th



now my question is
i have a spare scrap motor that im stealing the gearbox from, can i steal the crank and counter balancer and just pop them in with their matching bearings? or would i be able to just swop the good bearings into my bike?
my crank and balance shaft dont show any signs of damage and both measure in spek
thanx in advance