This adapter bolts to any 79mm Holset v=band exhaust flange and accepts a Ø2.5" OD tube. The flange is 1018 and has a recessed bore to give you plenty of material to weld to.
Kit comes with:
-1018 V-band Adapter
-Cummins 79mm V-Band Clamp
Preferred TIG filler for mild steel tubing is ER70S6 and 309L for stainless.