I've got a 1981 IMP with a OMC 260, 800 Series stern drive. Developed an ugly oil leak last summer which I at first assumed was a drain plug problem, when that didn't fix it, had to be rear main seal. When I started engine removal the first thing I found was where the crankshaft pulley had been chewing on the backside of the select trim assembly, I knew this wasn't good! I tried to remove engine and leave drive assembly in boat (supported) but I could not pry it loose from the adapter. I now have engine/adapter/intermediate housing on the garage floor but haven't tried to get them apart. What I suspect is that the driveshaft between engine and ball gear has frozen into the adapter on the flywheel and has been shoving crankshaft forward. Has anyone seen this before or am I missing something completely?