I don't remember the plug size for the EGR, but for the O2 it will work where it's at, but I moved mine on my pacesetter because it was hitting the O2 on my steering box. I moved down to the top of the collector right where it "Ys" together. You can buy replacement O2 bungs off ebay for cheap. That's where I got mine. I just cut the old one down flush and fill welded it with a MIG. Then I used the largest drill bit I had and drilled the whole for the new bung. I had to bore it out some with a die grinder, but once I got the bung ti sit steady it welded in place nicely. This position seems adequate for getting a good reading of the overall O2. I had problems with the readings jumping around a lot, but that was due to my inadequate fuel and high compression head. Then of course #5 blew out around the water jackets. Anyhow, the point I guess is, it will work where it is because the system is a batch fire and all the cylinders should be getting the same amount of fuel and burn...Should...In a perfect world anyhow. If you want a better reading you can more it, however with the ceramic coating that might be difficult.