Which Gears For Heavier Towed Loads?

Discussion in 'Towing & Trailer Tech' started by azhobo, Sep 23, 2013.

  1. azhobo

    azhobo New Member

    Could use some advice from any of you gents experienced in towing heavier loads with GM gas motors. I have a 99 K2500 454 with the NV4500 5 speed manual. Factory gears are 3.73 with 265X75-16E BFG KO's. Original milage on the truck is right at 90K, so the engine should still be very sound.(no mechanical loss of power) This is my first Chevy pickup since the mid 60's, always had Fords, some with diesel motors. What I'm finding is that GM makes a "softer" truck than Ford, and I don't have the power needed to pull my 11,000 pound trailer in low mountains. Otherwise I like the pickup, so what I think is that a gear change may be just the thing to get the power back where it should be.
    I'd like to go to a set of 4.30's, but so far haven't found a gearset in that ratio. Does anyone make a set of QUALITY ring and pinions in that range?
    Or.............. maybe the 4.56 gears would be alright, thinking ahead to using a 255X85-16E tire that BFG offers in an aggressive tread pattern. What I don't want to do is spend the big bucks to change front and rear gears, only to find out that I didn't get it right the first time. Normally I'd go with 4.10's, but I'm not convinced this would be much help with a gas motored pickup.
    One further question................ please tell me about any computer restrictions I might run into with swapping gear/tire sizes on a 99 model.
    Thanks for any help I can get.

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  3. Rebel_Bowtie

    Rebel_Bowtie Rockstar

    I know 2007 and up Tundras with towing package have 4.30s... not sure how compatible that rear end would be with a GM, but both are live axles with e-locking diffs.

    As far as 4.10s not helping with a gas powered engine, that's what all the 6.0L GM 2500s have and they are stout trucks. But they also have the 6-speed trans.

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