Welded combustion chambers?

I gas welded up the chambers on a Slant head a few years ago, but canned the project before I had it machined down..ended up tossing it on the scrap pile. I do plan on welding up another for a current project.
Welding onto cast iron is actually pretty easy..it's repairing cracks when things get trick and special materials and techniques are necessary.
Mild steel rod, LOTS of heat and patience is all you need.