OK guys, here's the deal. I have a freshly-rebuilt 5L TPI in my 85 IROC. It's been punched out 30 over, refitted with 1.94?/2.02 valves, rollers, dual roller timing gears/chain, fully blue-printed with all forged internals, and high-volume oil pump.

When first start it up and run it everything is fine. However, if I shut it down and then restart it within say, 20-30 minutes or so, oil smoke just rolls out of the exhaust. If I let it sit for a while it's fine.

It did overheat once, pretty bad, after the temp sensor failed. My first thought was failed valve stem seals but it seems like that being a "mechanical" failure would cause rather consistent symptoms.

The other thought is, I can't help but wonder if the high-volume oil pump is overwhelming the capacity of the otherwise stock heads to return the high volume of oil to the crankcase. Maybe a combination of both?

Is it possible that the oil burning is actually trans fluid somehow entering the combustion chamber through the TPI intake? Or, is there even a route for it to do so?

Would a plugged EGR valve cause something like this?

Any thoughts would be greatly appreciated!!!