Q: Rebuilt 350 engine rebuilt Quadrajet carburetor with new computer. Nothing will connect to the computer, which is effecting my transmission.

Original engine when purchased at 18 years old had 64,000 miles. It was is Pennsylvania and since owning 6 caprices all my life which all gave great service. Turns out original spark plugs still in and it wasn't till hitting 143 thou miles when the lifters could not be settled down from clatter. Purchased a new rebuilt 350 as could not find a 305 installed along with the rebult carb. While the old computer original engine and rebuilt carb all was good. Only when the 350 when installed was when the issue of 10 mpg got me to take it to electrical experts even bit the bullet and took to friendly GM service. 2 days later they wanted $1800 to install a new gm carb which in non existent . Didn't even charge me the $125 estimate charge I even purchased the computer for ob1 and ob2 no luck Engine stalls at will mostly at stop signs but scares when it just quits turning a corner. Question, 3 computers electric experts can't seem to find why the computer is not connection? Wirering or bad carb.

My car has 3500 miles.
My car has an automatic transmission.