Guys, Thanks for all of the input. I've not been able to check any of these items out yet due to the cold weather-since I don't have a shop, the truck has to wait. One thing though- The only time that the oil pressure drops is after the trucks been driven at highway speeds (45 to 55 mph) It'll idle all day with the 30lb pressure gauge pegged. I think the oil pressure drop is directly related to the oil being low, since both times this happened, the engine was 1/2 a quart to a quart low when it was checked. I'm using 30w oil, do you think that's to thin? I had the valve cover off to replace the gasket due to leaking and all looks relativly clean and good there. The side pan (I forget the proper name)on the engine appears to be leaking around it. So,I'll clean the road draft tube, replace the gasket on the side pan, install a vented cap and if that don't work, I'll jump into the more complex (for me) issues. Thanks again
