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Which gear ratio?

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Discussion Starter #1
I have a current thread discussing this topic here. I'd like to add a poll to that thread but can't. Perhaps we can just continue that conversation here and give you an opportunity to vote.

Here's the deal. You can see my setup in my sig. The truck is driven on the street at least 95% of the time. I need more bottom end umph. My current tires (265/75-16) are 31.65". Next tire change I'll be going to 32.8" (285/75-16 or 305/70-16). Below you'll find the gear ratios I'm considering and the RPMs they would give me at 70-MPH. Gas mileage is a concern but I want the torque new gears will give me. It's just a matter of how far I go.

________3.73__4.10__4.30__4.56
31.65___1940__2135__2240__2375
32.8____1875__2060__2160__2290
 

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Mayhem, Like Me
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4.30's if you can find them... if you cant go with 4.56's... the difference in 3.73's and 4.10's is hardely noticeable IMO
 

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Discussion Starter #4
And they are in Motives latest catalog. The fronts are a new part#, GM10-430IFS.
 

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Discussion Starter #6

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Discussion Starter #7
I just talked to Motive. The front 4.30 gears are brand new and the the first shipment from Italy isn't expected until July. Also, when I talked to Randy's R&P, they said the regular grade of Motive gears were prone to be more difficult to setup and noisier. He did say their performance line were good. Comments? Go with Yukon 4.56s now or wait and get the Motive 4.30s?
 

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Discussion Starter #10

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Discussion Starter #12
I won't be going bigger than 33s and the 4.30 won't be available until July at the earliest.

Would there be any problem installing the 4.30 rears and NEVER using 4x4 until the fronts go in later?

Anyone here used Motive gears and found them to be hard to setup or noisy?
 

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heavy on the skinny pedal
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I never really cept track of my milage since i put the cam in it just seemed to drop. and if you go 4.56s I'm selling both my axles. they both have yukon 4.56s and the back has a detriot in it. the back one will need brakes to.
 

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Discussion Starter #15
I might be interested in your Detroit. I assume that's a TrueTrac?
 

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Discussion Starter #16
Can I install the rear 4.30s now and drive it until July as long as I NEVER use 4x4?
 

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HOT AIR BALLOON OWNER
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Can I install the rear 4.30s now and drive it until July as long as I NEVER use 4x4?


Yup, sure can.

Since you're gonna do 33s, I'd do the 4.30:1 if it is for sure available. If not, just drop down 5mph on the freeway so the RPM is reasonable.
 

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Discussion Starter #18
I've emailed the Light Duty Sales Manager at Motive to make sure that they will be available and confirm the July date. It'd sure suck to get the rear 4.30s installed only to find out the decided against the fronts. The new part# is already in their online PDF catalog.

I'm thinking about throwing a Detroit TrueTrac in there while I'm at it. I've heard nothing good about the G80 that's in there. It's not a very positive posi anyway. It's easy to get one-wheel-peal with it.
 

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Discussion Starter #19
Is it necessary for a street truck on 33" tires to have one of these covers that supports the bearing caps? LINK
 

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HOT AIR BALLOON OWNER
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I have one on my F150's 8.8... keeps bearing caps from walking, more oil capacity, etc. T/A makes them too.
 
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