Maybe your idle circuit needs fattend up. once you get out about 2 turns you are limited by the restriction and bleeds. Wouldn't be the fist carb that was on a lopey cam that needed some idle circuit work.

As pointed out any small air leaks will make it read lean. Slip on collectors are a big culprit for sure. Also as pointed out idle means little to overall performance. Also don't start shooting for an "ideal number" once you use it. ALL combos are diffierent and will usually require something other than that "optimal number" ALWAYS jet for performance then note the O2 readings. Don't get caught up in chasing a number and not pay attention to what the car is doing. One last tidbit Stoich is different for different fuels. FWIW we run the AEM stuff on the dragster and it works fine for us.

It should read something unless it's so lean it's out of range even for a wideband sensor, and that is possible. What carburetor and how much camshaft? What is the ignition timing at idle? For a street-driven car it is important to be able to read AFR at idle and just off-idle since that's where the carburetor is most of the time. Your carburetor might need some minor surgery to get it right.

It's a new thumper 1050 dominator cam is 630/650 after lash and if I remember it's in the 270/280 range I took it for a drive and it's 13.2 at wide open so it's a start

Good to hear .
I like dialing them in at the track. Watch the MPH and once you have the highest MPH that's what it likes.

Hope to get to the track this Friday and we can find out what it will do. This is a new to me car with the motor out of my Aspen made a few up grades ported eddy heads trick flow intake thumper dominator and the duster is 700 pounds lighter then the Aspen and that went the best of 10.88 @ 125 so we shall see what this does

Had the exact same problem, so have other guys at my local track, with open headers you will need some sort of back pressure, I slipped on some mufflers on the collectors and got a instant reading, just to set the idol, then took them off, other guys I have talked to did the same thing, just not enough air flow at idol, put a cheap set of mufflers on or something to make some back pressure and you will get a good reading

I run dyno max bullets on it and they dump at the rear tires

Did you let the engine come up to temperature? I have an AEM and have used them for a few years now. When the gauge is cold it sometimes takes 30 seconds or so to get a reading. Also, on my 440 I don't have a choke, and I keep the throttle cracked a little and high idle it myself for a minute or so when I start the car. During this warm up time the gauge typically reads pretty lean, like high 15s, most likely due to incomplete combustion until the engine gets some heat in it. It probably takes until I've got about 130 degrees in the engine to get it to settle in.