Gear swapping is the way to go for you. I have 3. 54 gears, they do me fine and I'm keeping them. Not a quick as 4. 10's, but on the freeway the RPMS are way down and mileage is up. Nicer to drive actually. They also make a gear set that's between these two sets. I think it's 3. 73's which was installed factory in a lot of our Dodges. Maybe you can find somebody that wants to tow on here that wants 4. 10s on TDR and do axles or gear swaps for cheap. Your Signature doesn't say where you're from. It might hard to find a swap without your state listed at least.