Oil Gauge Fluctuation

[vanimal]

Engine Details: 4.3L Sierra 1500 2x4 195,000

Problem: Drive anywhere, down the highway or in town, the oil gauge will drop to zero pressure. after 10-30 seconds it recovers to the normal 60 that it usually runs at. It started doing this over the weekend and this morning I started to hear the engine knock. By the time I got to work it was louder (only when the pressure went to zero). The engine runs and sounds normal at the normal pressure.

I am thinking it is the oil pump? any thoughts?

[vanimal]

Ok, one more thing to add. I have been thinking about a new engine for the truck for a couple months now. It's getting up there in age and I know next year it will probably kick it. I was thinking about a 350 but haven't looked into it too deeply. I have always wanted a truck with a V8 and it already has a manual tranny. What are your thoughts on the swap? prices? workload? etc.

[Springthing]

Project that's recently been finished and is now grumbling down some street...

http://www.gmtruckclub.com/forum/showthread.php?t=14576

[95CTburb19]

It's a pretty involved process to go to a V8, and that loss of oil pressure does not sound good.