Ya I did a lot of research on getting the vbands to seal. From what I've read, having it clamped while welding it is the best way to prevent warp. Also stitch weld it.

One big problem I had was welding the cast to the mild steel and getting 100% seal. Seemed like every now and then I'd find a pin hole and have to grind and re do it.

I'm not too happy with how it turned out but eh, it works lol