Hey tbi gurus...my dad converted his 86 c10 from carb to tbi using all the stuff from like a 90s van. He also swapped from a th350 trans to a 4L60e.

The engine has swirl port heads, a large cam (enough to make it lope good-have to get the numbers on it later this evening) and is bored .030. Stock converter.

Hes concerned about mileage...he thought that with the overdrive and tbi he would get much better but he isnt...hes getting about the same mileage as with the carb and 3 speed.

He is using the stock computer...does it need tuning to make it run better? Any help is appreciated. Hes pissed that its not doing any better lol