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Greetings everyone, I am thinking about swapping gears in my LB7 and was wondering if any of you have switched and what ratio did you go to?
I frequently haul heavy loads in the bed and drag stuff up to 15,000lbs.
I switched out the factory 245's for 285's which I know is not huge but the truck could use some help on take off.
Any info on ratios and resulting rpm/mph would be appreciated.
Thanks and Happy New Year!!
 

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With those tires -- going to 4.11 wouuld put you back to almost stock RPM. I don't recommend 4.56.

If you have 4 wheel drive, you would have to change both front and rear gear sets. Probably looking at $2,000. The gears have to be set when installed and most people cannot do it correctly at home.
 

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Discussion Starter #3
That pretty much what I thought, Thanks.
 

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If you are going to spend the money, take into account what tire size you plan to run in the future. If this tire you have now is what you want you should go with the 4.11's. Google a gear ratio calculator and fill out the info for stock and then for the tire size you plan to run and it will tell you the respected RPM's for both so you will know exactly which gears to run. P.S- if you don't know the specs on your Allison and transfer case just Google it and you will find it.
 

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if your gonna spend the money on gears, then lift it 6-8" run 35-37" tires and put 4.56's in her!!!:rockin
 

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its tricky business to set up gear changes. Black lash & all that crap. If it was me, I'd find front & rear differerntials out of a salvage yard with the 4.10's you need & install them as an entire unit. Then sell your units & re-coup some $$$. Cost you alot less. A good amount of work either way you look at it.

Easiest way is to give the truck alot more power & not have to worry about needing more "UMPH" off the line!
 

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Greetings everyone, I am thinking about swapping gears in my LB7 and was wondering if any of you have switched and what ratio did you go to?
I frequently haul heavy loads in the bed and drag stuff up to 15,000lbs.
I switched out the factory 245's for 285's which I know is not huge but the truck could use some help on take off.
Any info on ratios and resulting rpm/mph would be appreciated.
Thanks and Happy New Year!!
TREEMAN??? Arborist?
 

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its tricky business to set up gear changes. Black lash & all that crap. If it was me, I'd find front & rear differerntials out of a salvage yard with the 4.10's you need & install them as an entire unit. Then sell your units & re-coup some $$$. Cost you alot less. A good amount of work either way you look at it.

Easiest way is to give the truck alot more power & not have to worry about needing more "UMPH" off the line!
New a guy that spent a ton of $$ going from 3:73 to 4:10 and afterwards couldnt tell the difference. Wished he would have gone lower. Talk to Raul with Stealth Automotive. Hes a Ford guy, but I believe he went with 4:56. Gas milage sucked, but if its torque you want, thatll doit.
 
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