Silly Question I Know But...

[mustangmarty]

What rear end gearing would give the best highway gas mileage for a carbureted 408 with C-4 tranny and 37X13.5X17" inch tires? It also has 5.5" suspension lift and 2" body lift. When I built the engine, I did it with a smaller RV type cam for low end torque.

 

[Mountain Ram]

I have a ragged out 5.0 with a C4 and 37s. I run 4.56 which is not enough for the Bronco to get out of it's own way and whines out around 70 on the interstate. I wouldnt go any lower numerically than the 4.56- You will have more power with the 408, but will still be limited top end. Numerically higher hurts the highway performance even more.

Todd