Kitty Cat Snowmobiles

Hello, I purchased a Kitty Cat which I thought was a 1973 but after doing research, it may be a '72.
A friend of mine wants to sell his '72 and our serial #'s both start with KC3. Does this mean we both have '72's or '73's???
Also, aren't the '72's different from all the rest?
I am new to the Kitty Cat world and would appreciate any help.
Thanx,

Im in the same boat. I have no idea what year my Kitty is. Its a basket case I picked up because they thought it had a bad ignition coil. The number on the tunnel is KC2 8141 the engine says 15?A71 and 006765. The engine is Silver with and Arctic Cat Sticker on the side. Any Ideas? Its missing a few parts but the track ,tunnel and Cab are in awsome shape. The coil is internal ? Most of my toys have 2 wheels this is a hole new game for me.

KC2 = 1972
KC3 = 1973

1972 have Kawasaki T5A Motors
1973 Have Kawasaki T5B Motors

Thats a big help man thanks alot.

At one time, my friend had two 1972 KC2's and one 1973 KC3, they looked identical at first glance, but the Kawasaki motors were labeled differently, I couldn't see much difference otherwise.