i just got my 143 big bore, race head and all that and i just put the piston on (i installed the 55mm crank too) and i put the rings on and all, slid the jug over and its not going down into the cases.. the 143 says its a bolt on and doesnt need case boring... any one have any ideas? i could be just completely blind and missing something but hell its been a long day of traveling..