Wait till you checked them,you might only need a few,not sure what bike you got but i would get OM (from Fowlers etc)not after market shims.You will need a Haynes or workshop manual to work out what you need to get to be within the tolerances.When you replace them mark sizes down on a drawing so you know if there is a next time what they are.
Mine are under buckets which means if i have to replace them the camshafts have to come off,some bikes have them on top ,lot easier to change. Make sure the correct marks line up on the rotor using the No1 cylinder usally and camshafts are in the correct position (should be punch marks lining up ).
Mines only a twin but with a 270crank that is bit of a pain to do rather than a 360.
Strange there different prices quoted for the diff sizes,my Yamaha ones are all same price,
Good Luck.
