Thank you all for the quick response.
So, I’m guessing this truck got an engine swap in the Sixties and
a Corvette exhaust manifold from over the counter added at that time. Maybe.
The truck reportedly was brought from California a ( To BC ) lot of years ago by a gold miner.
I will shortly strip the engine down and assess if that iron crack might be repairable.
Looks like a heat crack that’s open slightly.
Would be nice if I can use it!
Thank you all again for the attention.
Charley