if they are lightnings, the only place we got 02's to live was in a primary tube about 10" from flange, but like others said as well, at altitude the air is bad, you need less fuel and more boost to make power, one way to test, but really need the 02 to be safe, go out make a WOT pass record speed, lean it down say 4 sizes ft/rear go right back out and see speed, if it picks up, there's you answer..

Honestly, given the simplicity and affordability of EFI today I'm surprised to see anyone starting over from scratch would go carbs. I know they can be better for all out performance, but for those of us that hate being under the hatch, installing a couple of bungs and a couple Holley Sniper throttle bodies isn't a bad way to go. Am I wrong on this?

How much r those and how hard to do

Wow, I just looked these up. Very cost competitive with a quality carb and afr kit. I might need to do this Sniper myself. If I hadn't already installed a low pressure fuel pump for my carb it would be the same.