ok i want a gear ratio that will be best for speed and acceleration My stock ratio is 3.55 the others are - 3.73, 4.10, 4.33, 4.56, 4.88 which ratio would be the best?
First thing is first.... Before determining a ratio , you gotta give up some info bro. What size tire are you running / planning to run? What Engine do you have in the truck?
I read the first post and said the same thing, and was just about to ask... tires and engine play a HUGE! roll in this decision...
this man beat me to it. i was gonna ask what size tires are you running? cause i have had 3.55s, 4.10s (twice) and now 3.73s all with lockers as well. the 410s were badass but it killed my highway driving. the 373s still made a big difference, but on the highway it is perfect. if your truck has and decent size tire on it, you should go with the 410s...unless you have like 40s then id say bigger haha
the ratio depends on your tire size. Now, if you are still running stock, than 3.73 is gonna be the way to go. But lets say you dont have stock size tires (overall dia) and wanna know how to get your truck drivetrain back into factory specs. Simple math! (New Tire Size / Orig Tire Size) * Orig R&P = New R&P Example: (35/30)*3.73= 4.35 This is what I used when determining my new R&P and I get awesome gas mileage on the hwy, great torque added back, and still get great city mpg.
OOOOO I like that!!! Good math, I did it with mine and it reads 4.30 though... I've got 39s but I had started with 3.31 R&P which ya don't want in the first place... I've got the 5.4, 9.75 rear and I had 3.31 gears ... now I have 4.56s and it seems perfect to me...
^^^ thats because the 4.56 still puts the truck back into factory specs, just not YOUR specs. 4.56, or 4.60, is what would equate to you having 3.55, which Ford mass produced as well, and is another reason you prolly get real good mileage on 39's.
