Carcrazygts2

4.56's an 37's are the equivalent to stock tires and gears in the 97-98 trucks. Stick with 4.56's. Also if you have shift on the fly the transfercase has a slipping clutch in it so its only safe to around 50 mph.

lifted97

If I'm going to be running 37's, why wouldn't I wan't 4.88s? and I'll just pull the drive shaft

isthatahemi

So the 37's are all show?

lifted97

Why would they be all show? I wheel the crap outta my truck. Search youtube and you'll see lol but I'd be pulling the front drive line so I can drive the truck until I get the money to buy the front gears

Carcrazygts2

Its all in the math. 37's with 4.56's will run the same RPM and feel about the same as your truck did with 3.55's and the stock 30" tires.

Kdawg_69

me seems to think your math is a little off i have the same engine tranny combo and start with the same axle and did the math as well and came up with that 35 + 4.56s = stock and 37 + 4.88s = stock when i redid my gears about a yr ago and when it came down to it was spot on and no i will never run 37s on my truck cause i don't do enough offroading to justify them but believe i do my fair share but its a different style i built my truck to get me into hunting camp and back out and add in the amount of driving to and from work and also work errand means 4.56s were perfect for my 35s

lifted97

Thats what I thought as well.... I'm going to run 35's for a while but I could very well run 37's as soon as I find a good deal on some... But I only wanna gear once so I figured 4.88's would be a good choice. It was a hard decision between 4.88 and 4.56 but I tow a lot and go over big hills a lot

Carcrazygts2

You can do it all you want. Here is the math.

New tire size /divide by old tire size * stock gear ratio.

Kdawg_69

where in the world did you come up with that brother i'm not knocking you by no means so don't take it that the wrong way but when i was regearing my truck according to repair manuals and the gearing ratio of the tranny to the diff but hey by your calculations you are correct but by the calculations that i have done before its the way i stated above

A7X

This math works perfect and is a well known equation to get back to the stock rpm range...

After that you can make the final decision on the ratio based on what you do with the truck... If you mud it out offroad it you probably want to hop it up a bit... If it's a street Queen 4.10 would be fine for 37s... I've run 4.56 with 37s and it was peppy, 1/4 throttle and it was burning tire on the road...