[46stude]

Update: I did cause the problem.

When I first put the truck together, every so often while running down the hiway, the PCV would pop out of the valve cover. I knew when it happened because the oil smell would come into the truck. So I'd pull over & pop it back in. I believe this was the direct result of not properly plumbing the engine for the PCV. I had no breather on the opposite valve cover for the PCV to circulate air into the 350.

Apparently, at some point the hose must have layed on the exhaust manifold long enuff to partially melt it. So the hose was sucking air, which is also probably when the PCV magically stopped popping out.

So, when I noticed the hose was bad & I replaced it, the PCV had, over time, locked itself into the grommet. Instead of being able to pop itself out of the valve cover, the PCV instead popped the intake seal at the back of the engine, resulting in the oil leak. And it apparently only leaked while under load & actually running down the road. You'd think the oil leak's location would be obvious, but it wasn't.

So, I yanked the intake a couple days ago & replaced the gaskets & RTV on the china walls. There was an "extra" grommet I'd plugged, so I bought a grommet & breather at O'Reillys & put them into the drivers side valve cover.

I put 40+ miles on the truck yesterday, & no oil leak. Problem solved..... I think.