2.62 gear ratio

How is your engine doing now with the 3.55's? Does it ever feel like it is struggling, or are you getting tired of the high rpms? Do you have to change down a gear frequently?

One thing to also keep in mind is startability. Do you have to use LOW gear now, or 1st as start gear? Do you go off-road where you need a low gear?

On level ground, and moderate speeds, I'm pretty sure that the 430 detroit should be good enough to do the job with the 2.93's. But I don't know I20 or Texas/Louisiana, so I'm not much help there.

Swift ran 2.93's with 430 12.7's, in the early 2000's. You have the 13 speed which will help, Swift had (convertible) 9 speeds. Basically the same transmission, but without the splitter.

 

It does good but it burns fuel bcuz the rpm are so high. I-20 between Dallas and Louisiana is mainly flat ground. I don’t really use low gear and I don’t go off road much

 

Just to say it are you sure you don't have other problems? What are you getting? What are you expecting?

 

I’m getting 5mph. The transmission was replaced and the final gear ratio in the transmission is different from the original one

 

Why didn't you mention this in your first post?

Original was probably 0.73 in high gear.

Overall ratio of 0.87 with 2.93's is 1.7% faster than of 0.73 with 3.55's. Nearly identical.

 

Being honest it will be cheaper to put the right trans back in it in the long run. Changing both rears is gonna hurt, and the RTO14613 and 15613 are not the most reliable trans. The back boxes are known to give trouble