I have a 79 Bronco with 44's and 4.56 gears. It was that way when I got it. It also has a worn out 460 and a fresh C6. It does great around town, but can't hardly do 60mph on the highway. I know in theory I should have lower gears, at least a 5.13. From what I know if I had a lower gear then I might have a worse problem on the highway. With the rebuilt C6 my 0 to 10mph time is pretty good. I think it's just lack of power from my old 460. Any thoughts?