I put an AEM wideband O2 in my truck. Definitely makes tuning the weber a lot easier. Unless you just have a tired engine, I think you can probably get a lot more out of it. My 2.6 is in front of a 4 speed slush box and I cruise at 75 all the time on the primary barrel only. When I first got the truck and the carb was not set up right, I would be in the secondary to hold 75.