77 Chevy Truck with new 91 TBI motor swapped in. Used TBI parts, new painless harness with all correct sensors including VSS. Took it for the 1st real drive today as part of the engine break-in period. I drove about 10 miles and noticed the ALDL check light (painless wiring harness) had come on. When I came to a stop to check it, the light went out. So I continued on my merry way. After another 5 miles the ALDL check light returned and stayed on, except when I would come to a stop and idle for a minute. Then the check light would go out. As soon as I'd start driving for a few miles it would come back on. I ended up driving about 68 miles roundtrip and it sucked up 8 gallons of fuel. So, on the way home I dropped by Autozone and got a code key. When I got back home I checked the ALDL and pulled up a code 42 and code 44. Now I know each code can be a number of things but I thought I'd get a group opinion to help narrow it down. The truck was running doggy. If I tried to accelerate normally it acted as if there was a lean running carb on it. If I accelerated very gently it ran okay. Also the mileage was horrific, between 7 and 8 mpg. Whatcha think?