Alright im havin trouble finding out the best possible gear ration for my truck. It has a 727 with 3.55 gears and 33 inch tires now but im goin to swap in a mag motor with a 46re tranny and bump up the tire size to 35's. She will be my daily driver so i want the best mpg's i can get.

 

i think the best gears to go with 35's and and a 46re would be 4.56 gears.

 

I'd probably agree. Go do some gear ratio crunching (ringpinion.com, etc) and find the gear ratio that will keep your RPMs in the best range for the majority of the driving you will be doing.

 

like i said it will be my daily driver so im looking for the best mpg i can get without the performance loss and i asked different people and i got every ratio from 3.91 to 4.56 so i wasnt sure.

 

swapping to 3.91 gears would be ok if you keep 727. most of the newer off road package trucks come from the factory with 4.10 gears and i think 31" tires. now if you step up a tire size or so you would also need to step up the gears. if you do not get the proper gears it will be jumping out of overdrive all the time and not saving you any money. now running down the hiway with a 46re in 4th gear and 4.56 gears with 35" tires your engine would be running at about 1963rpm where as with the 727 in 3rd gear with 3.55 gears and 35" tires you engine would be running at about 2340rpm. not a big rpm difference but it is something.

 

What engine is in your 3/4 ton? That is a very important factor on deciding what gear ratio to use.

 

8 Year old thread?

 

I thought I was replying to another thread, you can delete if you want to.