It's interesting that this thread has come up now as my 261 is dropping oil pressure. It starts out with 50 psi cold and when hot gives me a healthy 15 -20 psi but at low idle it will suddenly drop to 0, I'll shut the engine off restart it and it will show 15-20 again. I have my fingers crossed that it's the gauge and it will be the first thing I replace with a quality unit but it has me a little worried right now. I don't think too large bearing clearances would cause an intermittent problem like this but what else besides the gauge could it be?
-mike-
