I can take it to madera if you can meet me there sometime.
I am down south all week this week but if any one wants to come to fresno it's all yours.
and yes its weld on. there is no bung hole for an O2 sensor.
Another thing too is the air tube has to be pinched or welded shut, it was removed for a custom application when installed.
I do have a guy down here that will install it for $30.
$30 to install it, would love to but can't make it down that far any time soon.
If you can bring it to Madera on tuesday my friend runs the big-o tires and he'd pick it up. I can paypal you the money if you want. Just need to get back to me by tomorrow at 7 or it'll have to wait till after the weekend as I am gone to the rubicon tomorrow.