Hello, I've got a 348 that I've rebuilt, new oil pump, and everything seems to be OK, except my oil pressure. To start I'm currently running 10W-40 and at start up I have about 50 - 52 lbs of pressure. However after getting the engine up to temp and driving 20 or so miles my pressure drops to about 1 to 2 lbs at idle. The engine isn't running hot, nor do I hear anything out of the norm. It's a flat tappet, so I wouldn't hear the lifters, but overall it doesn't sound any different when it's dropped. I've tried 2 different gauges with the same result. I've got the gauge connected to the port right above the oil filter. I've added the spin on adapter if anyone thinks that could make a difference. I found this thread, but it didn't come up with to many ideas on why it could be low, but it did talk alot about why some people don't like Pennzoil. http://www.348-409.com/forum/threads/oil-pressure.63/ Any ideas on how to proceed would be appreciated.