ok i am getting together all the information and pricing for my next project on the truck, i will be getting 37" tires so i just assumed i would need 4.88s. While i was calling around getting different quotes they didnt seem to think anything about the 4.88s for 37s until i called one shop and the guy i talked to said that 4.88s would be over-gearing and that for 37s i need 4.56s if i want to have any highway (he said at 65 mph instead of running at like 2200-2300 i would be running at like 2500-2700)

is he wrong? if i get the 4.88s will i be running 200-400 RPMs higher that i should be ?

thanks for the help guys

 

I'd go with 4.88s. The mechanical advantage takes a lot of strain off of your tranny. If you're that worried about gas mileage I wouldn't put over sized tires on.

http://www.richmondgear.com/101032.html

^This calculator says that with 4.88s and 37s at 65mph you'd be at 2016 RPM

 

ya i figured he was wrong, well not completely but since i do more than just hwy driving i will mpst likely go with the 4.88s, thanks

 

but i do not think that calculator is correct i run higher than that with just 33s and stock gears

 

Yeah that calculator doesn't seem to be right. I just did mine and it was way off

 

wow I have been thinking the same thing for a little while now... 4.88s or 4.56s... still undecided which to go with....on my old 97 f150 with 38s the 4.88s were perfect but now have a heavier vehicle but smaller tires 37s and a bigger motor now have 5.4.... but my problem is I drive 50/50 highway city....so still don't know which to go with figure more power with 4.88s ... sorry to hijack thread but this has been a on-going problem I've been debating too lol.... let me know what you end up with and how it works out for ya... i need better than 9.9mpg...lol

 

you didnt hijack at all if i get them before you ill let you know how they are but it will prolly be at the end of this month at the earliest

since i do more city driving than hwy ill most likely get the 4.88s but i dont want my highway driving to get to hell so i dont know what to do haha

 

anybody have 37s with 4.88s ?

some feedback would be awesome!

 

Go with the 4:88's if you do a lot of city driving. Will accelerate better.

 

ya thats what i was thinking but i do have to go on some lengthy highway trips also but i think in the end the 4.88s are going to be the best bet

i still would like to hear form someone tht is running this setup though

 

i have 38/13.5's w/4.88's, and i ve got to say its awesome to be able to keep up with traffic from the get go lol. the truck is much more enjoyable to drive. the acceleration is just as good if not better than when i had stock tires and 3.73's.

on flat highway i run 70mph at around 2,200-2,400rpm.

in my opinion i would go with 4.88's with 35's and anything bigger. its only a few hundred rpm difference between 4.56 and 4.88's. the acceleration and low end power is worth it especially if you tow or do alot of city driving.
it's nice to be able to accelerate up a hill on a highway instead of moving into the right lane

the longest trip i drove with the new gears was about 260 miles and the only time i went above 2,800 rpms when i was going up a long steep grade.

Go with 4.88's you wont be disappointed

 

4:56s in the house! I am running 35s and I usually run 2400-2500 rpms at around 75mph. I too love the acceleration and all that wonderful stuff. I am going to step up to 37s though, but I dont plan on re-gearing. Instead, I will be engine swapping.

If you have a 5.4 then I wouldnt see any problems running 4:56s which would save highway. Guys run 35s and 3:73s with a 5.4 and the trucks still get up and go. Trust me, 4:56s.. 4:88s whichever whenever.. you will love the difference. I think your truck will have plenty of pick up with 4:56s and 37s anyways.

 

gosh ! haha now ive heard from both lol but im going with the 4.88s incase i ever want to go to 38s ill have that option

 

do the 4.88's.

 

done deal.

by the way when are you going to be in houston? we might need to have a meet/instal a fabtech kit