Did I toast my 340?

I think he has a blown head gasket AND a leak at the crossover letting the two fluids mix right at the crossover leak.
That's what it looks and sounds like to me anyway.

(Oil pushing up through the burned gasket then mixing with coolant in the exhaust from the blown head gasket and both coming out together)

The head gasket could possibly be blown near the oil feed passage for the rocker arms...