I have a Dec 65 built 66 A code and I was drilling out the lower choke stove pipe that had rusted out inside the exhaust manifold to replace it with a new one. I think I may have drilled too far. What I am wanting to know is if the chamber/s that house the upper and lower choke stove pipes are connected or did I drill through and connect them myself because if I blow air in the top hole it comes out the bottom hole. Is this supposed to happen?
The pictures below should help to explain I hope.
Thanks!