You need something called a 'spark plug non fouler" you'll need 4 of them, there are 2 in each pack. One of the 2 needs to be drilled out so the o2 sensor can fit. google this process, there are all kinds of videos and instruction.
Shouldn't be more than $5 for a pack of 2.

The threads are a direct fit with the O2 sensor and O2 bung.

I bought nuts at Lowes to thread onto the sensors , stacked and welded 2 , then welded to the pipe, thread in sensor an voala, I have read online using spark plug non foulers drilled out but was unable to source the size I needed locally

Before you ask no I don,t recall the nut size, sorry

Thought I should chime in on the last update. The Non-Foulers are universal. you don't need a LR specific one. All plugs have the same thread and all O2 sensors have the same thread. Just go buy some and they will work. Well...they will thread and screw in, I can't say with certantly that they will work.

The stores around me sell at least 3 sizes none were correct size, if you could post the brand and p/n it would help them. : )

I bought.

Got these. The thread is too small.

Think somewhere here other is a part # for spark plug non foulers, that work

I bought some nuts that thread on the o2 sensor , stacked and welded them together then welded to the bung, had pipes off at the time

I like that idea. Found an old o2 sensor and am going to find some nuts.

bump. Charlie you ever find that thread size?