Low gears

My truck is rather sluggish. It has 3.42 gears. I am thinking of putting in 4.56 to increase accelleration a bit. I don't want a race car, but it would be nice to improve the pickup of my pickup (pun intended).
Is this a good idea?
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What truck, what size tires?

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If it has a TH700, 4.56-5.13 gears should be fine, just don't plan on running down the freeway in 3rd...If it has a TH400 or TH350, I would suggest a 3.73-4.10.

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On Tue, 30 May 2006 08:29:39 -0500, "Shades" <shades_1970(at)netins(dot)net> wrote:
GM ECM's support up to 4.56 axle ratios from the factory. (they need to pe reprogrammed though to use it.)

----------------- The SnoMan www.thesnoman.com
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wrote:

Yes what ires size, vehicle type and engine and planned usage. ----------------- The SnoMan www.thesnoman.com
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This site has a calculator based on your input of tire size, transmission type(ratio) and tire diameter. It allows you to compare diffrent rears and look at your road speed vs rpm. Depending at what speeds you normally travel and the engines power band you can make your own decision. http://www.angelfire.com/fl/procrastination/rear.html
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Its an awesome 'Calculator', but like all the others, it doesn't factor in slippage in an automatic trans. 10-15% is the norm even with a lockup converter.

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A lock up convertor working properly is 50 -75 rpms. not 10%. Pumping losses maybe 10% power absorption at the most. "Shades" <shades_1970(at)netins(dot)net> wrote in message

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I was referring to slippage causing 10-15% higher RPM.
The RPM that a lock-up converter drops is directly related to speed, amount of power, weight, and RPM itself. Under little to no load, it might only drop 10-20 RPM, under heavy throttle and heavy load, it con drop many hundred RPM.

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