SD and MAF DBW problems

[Gunnin4ya]

On my swap in my 65 I put an 02 5.3 in it with a stand alone harness. I bought an hptuner setup and trying to go sd to get it going. I unplugged the maf and plugged the brown wire from the maf to the iat sensor and black as well. Runs horrible. Goes waaaayyyyy lean when you hit about 3200 rpm. I unplugged the wires and went to drive it again and it ran great. But the iat temp was reading at -38. Which was making it run rich but didn't matter what rpm it ran amazing. I checked the brown wire I hooked up and traced it back. Goes to Red pin 25. Which says it is the iat. What am I doing wrong to not get the correct information? I disabled the po101, 102 to mil on first. If I disable p0103 it disables my dbw pedal. Think this is what is causing it?