We weighed the chassis the other night. 870lbs bare chassis with out the bottom skid bolted on so close to 950lbs total. Each axle was 807lbs with out tires so right around 1200lbs per axle. It will be a 5k girl. We have friend that just got some race scales to weigh things so we will have to have a weighing party.That's huge. So cool to see that you have that much help.
The O2 is a brand new ac Delco 3wire that is supposed to be in the 14.7 range like the factory single wire. All the sensors minus the spark control module are new bwd or ac Delco. I'm thinking it's one of three things, bad ecm coolant sensor, bad timing, or bad groundWOW, that's a ton of work. If you're not careful you'll be in a running buggy before too long. Nice job. To me that missing sounds like an O2 sensor, but I'm guessing you had those deleted from your ECM.