source for 3/4" tall o2 sensor bungs

I am planning to set up a pair of headers for dyno testing with 8 O2 sensors. (because I have 8 carbs) I bought some weld bungs from summit, but they are only 1/2 thick. The O2 sensor protrudes 1" past its flange, so that would leave 1/2" of the sensor in the tube. The dyno guys says that is enuff to affect performance. Does anyone know of a source for 3/4" thick steel O2 bungs. M18x1.5 is the thread. Thanks,
Joel

Check out Amazon. Lots of different ones on there.

I've been searching the web including amazon, ebay and summit. The search functions and descriptions mostly omit length. I'm hoping someone here knows a source.

Weld 2 bungs together

Check O'Reilly's.

I have an old Dynomax 88103 here that's 5/8" thick. Not sure I've ever seen one thicker. The threads on the sensors aren't that long. I suppose you could weld a bung to a thick washer/spacer and weld that assembly onto the pipe.

Are you interested in the dyno readings on the HP and torque or the accuracy of the O2 readings from each pipe?
I allowed a dyno operator to install 8 O2 bungs in my race car headers to dyno a B 1 motor I built for a customer several years ago, that motor had a cast single plane dominator flange manifold, not much carb. tuning was done on that test
On your deal I would install them and tune the motor and then remove them to see if the probes sticking into the headers affected the readings or not

You can cut these down https://www.summitracing.com/parts/...zhcfT4QIVL__jBx2m6AAcEAAYASAAEgIxvfD_BwE

Take a look at the old spark plug anti foulers, the stores may carry them under the help line.
Might be something you can use.

You guys have some great ideas! I just ordered a set of 8 spark plug anti foulers from rock auto for $2.24 each.

I could have just made, and welded spacers to your existing bungs before welding them to the headers, at my work.

Thanks to the LX Forum guys, they use 'em to space out their O2 sensors for various reasons.

BTDT. Just remember when it's time to weld them in, those things are plated. Don't breathe the fumes! Those used to hang on the rack at every parts store and I can't imagine why.

At full throttle the depth won't matter as much for accuracy but if you're looking to tune part/light throttle conditions it's actually helpful to have more of the O2 sensor tip in the exhaust stream. There is a reason the bungs have a standard height.

I actually milled the bung depth down on a set of headpipes for my Harley as the closed loop control wasn't very good at light throttle due to poor O2 signal at low exhaust flows.

I don't think you want an O2-sensor poke its head straight into the red hot exhaust fumes that close near the head. You'll cook them.
AFR doesn't change at 0 or 2" depth away from the headertube, so to make 'm last I would put them away from direct exhaust fumes.