I tell you how I just handled my 450 that had looseness at the crankshaft end of the connecting rod , I bought a new OEM crank and rod $300 , bearings $35 each , all gaskets and seals , new timing chain and sent the cylinder to G+H who bored bored it , sent an new piston , rings and wrist pin with gaskets $200 , and threw in new clutches , all the parts and bore job was $700 even , you might save a few dollars with a machine shop , doing the crank work and cylinder service , but for me it was a lot faster and less chance of things going wrong going the way I did