[rpduc]

Bulk metal tubing only comes in certain sizes.
I doubt FMF would spec an odd ball size for their pipes.

It's the swage on the inlet pipe that's wrong. I don't know exactly how they do that but I assume it requires a mandrel of some sort.

I have a Lincoln TIG welder. I'm not too proud of the weld in the pic above. I was in a hurry and didn't get set up right.

I redid it at a lower angle, took my time, and the weld is a a lot more prettier now.