[b-man]

Did you remove the timing cover and replace the gaskets ?

If there is one design flaw in a Pontiac V8 it’s the fact that a gasket breach in the timing cover at the block face can send coolant into the crankcase. If the timing cover has enough rot it can do this too.

Exactly what services did your local Pontiac guru perform?

Whatever you do be sure to drain all the coolant out so it can’t mix with the oil then flush out the water/coolant mixture by running it a few minutes with some cheap oil then drain it out.