Can someone help me? I have recently replaced the head 0331 oem with an Alabama Cylinder head. The problem now is the mileage. I went from around 18 mpg to 13 mpg. I also have an Aem intake and spacer. The plugs were new as well as the oil pump and all the upper valve components. Also this will "kick down" on the snow but not on the highway-passing gear?. Ive took this to two shops now to have this one cable adjusted. I was told it was adjusted as far as it would go It still doesn't kick down the way it did before. I really need some helps here-Thanks. It ideals dead on, there are NO lights on the dash Warning "idiot lights" I'm pretty sure there are No vacuum leaks etc. Ive reviewed the shop manual-I cant figure this out is the ecm relearning? Ive went around 1500 miles so far. Thank you!!!!