I have a 1987 Yamaha Big Wheel 350 (BW350) and i am getting ready to rebuild the engine. the bike is in overall OK shape except the engine which was messed up. the previous owner sunk it in a creek and hauled it home, took the engine apart, and it has been sitting in a garage since the mid 1990's. the cylinder wall is rusted and pitted and the piston needs to be replaced. essentially the cylinder is shot. the bottom end for the bw350 is unique to the bike and has no interchangeable parts to any other yamaha products that i know of. however, looking at part numbers on bikebandit, the top end and piston are the same as 2003 and below warriors and wolverines. unfortunately the crank is no longer made and was unique to this bike. i just wanted to verify that there were no differences between the different years of the warrior/wolverines. anything that i need to be aware of or look out for when buying a used top end such as years to avoid, etc? any and all help is greatly appreciated