Roger it's a 1971 460. I shut the engine off immediately when I heard and saw the oil spraying, within a few seconds, it kept spewing out uinder pressure for a bit. I've been reading up that the oil pump has a pressure relief valve that can blow back itno the pan, and also if it's gasket fails it can leak back pressure into oil pan. Think I might have mechanic friend take it to his shop where he has several lifts to get a better idea on where the source of the leak was. I agree there aren't to many choices here. I will have to wait a while before I have a break from work and other priorities to look for the obvious and crawl under it. The truck was only running a few minutes when this happened, oil wasn't hot and headers seemed cool enough not to smoke when oil got on the driver side header pipe.