I called Intense to order the stuff I needed today. & I was told that the drve gears & the chain is what I needed to change to change my gear ratio fron 3.05 to 3.29
and I had the Idea that it was the differential that had the gears inside.

can someone explain?

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2001 Blue SLE - 1995 Black SSE - 1988 Black GTA

Perhaps they didn't quite understand what you were asking for.

To do what you just described, which is change just the final ratio, is all in the differential gears. If you have a 3.05 final now, the diff gears are 38 tooth & 20 tooth. Where the 3.29 final you are asking for needs 34 & 22 teeth (both sets should be the fine pitch gears introduced in '96 ...this is assuming it's the 2001 you are working on. If it's the '95, then you need to look at the gears..they might be the old style, the '95 reversed pitch style, or the '96 fine tooth style.)

What they are telling you with changing chains would change all the gear ratios in the transmission (as the chain is the first reduction "gear" in the transmission.) Your choices are 35/35, 35/37, or 37/35. Are you trying to replicate a specific GM model transmission (i.e. altering an unknown transmission into something like a "9AHW" broadcast coded 4T60E)

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Bye Bye 1990 Bonneville LE... Now it belongs to my daughter
In the Garage: 2009 Subaru Outback, 1987 Camaro, 2006 SV650S, 1995 Regal 182 "ASANAGI", 1962 Ford Galaxie 500, 1995 Ford F150 XL 4WD, 1953 Farmall Cub

but do I need to get the PCM reprogramed if Im just changing the final ratio?

yes, it is for the 2001.

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2001 Blue SLE - 1995 Black SSE - 1988 Black GTA

Yes you will, as it will affect your speedometer. It will think you have a 3.05 FDR, whereas you will have a 3.29, and it will be way off.

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Bye Bye:

RIP sandrock

yup you will

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Just Your Average open loop tuned Ethanol Driven DD's

2k1 GTP: 13.307 @ 104: Headers, 1.9's, Tune
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Alex you have a 3.29 Diff, you Trans has a 35/35 drive and driven... so the 3.29 will be just that a 3.29.... Yes you will need a PCM to account for the gear change..