I recently purchased a 1970 Chevy C-10 longbed. It is decent condition but needs some attention to some of the smaller issues. The truck runs fine, but very poor mileage. I was told it has a 350 from a 70s Camaro and seems to run ok. It feels to me like I need another gear when I am on the highway and it gets very poor gas mileage. The current tranny slips when cold and as it get warm it runs ok, someone suggested upgrading to a 700R. Any opinions or suggestions on improving the mileage?? I do a lot of highway driving
