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Discussion Starter #1
I've been reading allover on this subject. And it seems that I may have one or two issues if I changed my gear ratio.
One is the possibility of losing the ABS and the other is lowering the top speed. :dunno:

What do you guys think? What is the best gear ratio for better acceleration and top speed? 3.73??
 

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LIFETIME HILLBILLY
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what is your stock gear?
 

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Discussion Starter #4
Scratch that previous post. I just looked at the SPID sticker in the trunk and there is a G80 code there. Does that mean I have the 3.08 ratio???
 

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Discussion Starter #6
Yes I am looking for the best balance between them but I need to know my current gear size for a start. How can I know?
 

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OEM LOL
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1996 - L99 Caprice(4.3) 2.93Gears (Revised from the Early 2.73)

1996 - L99 Caprice 9c1(4.3) 3.23Gears

1996 - Lt1 Caprice Wagon(5.7) 2.56Gears

1996 - Lt1 Caprice Wagon Tow Package(5.7) 2.93Gears

1996 - Lt1 Caprice 9c1(5.7) 3.08Gears

1996 - Lt1 Caprice B4U Tow Package(5.7) 2.93Gears

1996 - Lt1 Impala Ss(5.7) 3.08Gears

Also you can find the other code on there

GM8 - 2.56
GU2 - 2.73
GU3 - 2.93
GU4 - 3.08
GU5 - 3.23
GU6 - 3.42

G80= Positraction
 

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8th Gen Antagonist
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13,660 Posts
You won't sacrifice top speed, not that it was likely a concern anyway. You can go faster with 3.73's than you can with 3.08's simply because with the higher ratio it can't produce the power needed to overcome the aerodynamic drag, 3.73 is probably the most popular ratio to go with, but you can do a 4.11 if you want better acceleration. Mileage won't suffer much if any. You will need to tune for the new ratio however, shift points will be off, and speedo will be off.
 
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Discussion Starter #9
You won't sacrifice top speed, not that it was likely a concern anyway. You can go faster with 3.73's than you can with 3.08's simply because with the higher ratio it can't produce the power needed to overcome the aerodynamic drag, 3.73 is probably the most popular ratio to go with, but you can do a 4.11 if you want better acceleration. Mileage won't suffer much if any. You will need to tune for the new ratio however, shift points will be off, and speedo will be off.
wow... And what about the ABS not working after regearing? Looks like a lot of work to be done. And being here in a country with no good mechanical resources as in the US I think it's not worth all that trouble :gaah:

What if I just salvaged an SS rear end from the junkyards? Will that slight gear upgrade do any noticeable change? :dunno:
 

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Super Moderator
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Shift points actually endup just fine, the pcm get's it's MPH info from the VSS which happens BEFORE the gearing affects anything. The speedo will be way off though.

Far as ratio as said concerns about top speed is just ignoring the impact of overdrive.

The Caprice SS was what the Impala SS was sold as in the Middle East(this is where you are right?) even had the deer logos, the Caprice name had history there, the Impala did not so they used the popular name.
That said if a true Caprice SS we are looking at a current ratio of 3.08.
With no converter slip 3.08 at 150mph is 4000rpm which is below peak HP and the aerodynamic drag will usually stop the car from accelerating because the engine is not making enough HP to fight it further.
With 4.10s at 150mph it is 5300rpm which is past peak HP, BUT if the valvesprings are decent the engine will still be making more HP at 5300 than it was at 4000rpm with the 3.08s. The 4.10s will make you rpm limited with the stock engine to about what your top speed would have been with the 3.08s but the 3.08s were just keeping the engine below peak power and limiting you that way. The car will obviously feel a LOT better at lower speeds with the 4.10s. Even 3.73s will make the car feel 1000lbs lighter.
With 3.73s 150mph is 4900rpm which would be pretty close to peak HP with stock valvesprings they might actually be the gear that gives you the best top speed. Stock valvesprings get weak and at higher rpms can begin to let the intake valve bounce when it closes which hurts power a LOT and could happen at the 5300rpm 4.10s would turn at 150mph.

It just struck me I should comment on if this is a basic Caprice not a true Caprice SS, I see the rims in the avatar but just hear me out.
The 2.93 gears would have likely come with taller tires too the 255/50/17 "SS" tires were 27.04" tall where I think the regular cars got 245/70/15 which is something like 28.5" and that drags rpm at 150mph all the way down to 3600rpm the engine would be unlikely to make enough HP at such a low rpm to get the car to that speed and I suspect aerodynamic drag would stop acceleration well before that.
Trying to hold third gear would be 5100rpm at 150mph but the speed limiter, and factory rpm limit wont let you do that as well as needing to consider if such tires are rated for such speeds.

Actual rpm you see at these speeds will likely be higher due to torque converter slip but this is the "simplified" version and you can see that with overdrive rearend gearing and top speed do not act as most assume.

On the ABS thing there are reluctors available to let you keep the ABS functional, GM even made them for 3.42 and 3.73 and custom were made for 4.10s. It is additional cost but completely doable.
 

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The Unscrupulous Lt. Colonel
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What if I just salvaged an SS rear end from the junkyards? Will that slight gear upgrade do any noticeable change? :dunno:
All SS rears got a 3.08. Not very much of an upgrade from the 2.93. Get off the line a little quicker, but if you dont want to spend a fortune on rebuilding a rear, try to find some of the 91-93 caprice with the GU6 code which is the 3.42 gear. Thats something worth going after, but word is some of the fleetwoods came with a tow package which came with a 3.73. Good luck finding one. But i will say, the 4.3 Liter 9c1 that came with a 3.23 gear, in my opinion that was a really noticeable gear from a 3.08 my SS came with. You will probably have a little better luck going after a junked car with the 3.23 or 3.42
 

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should learn to check your ratio by counting the revolutions of your driveline then you can check anything easily. just put a chalk mark on the driveline and with one rear wheel on the ground spin the other rear wheel twice, the amount of driveline revolutions is your ratio
 

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When talking 2.93-3.08-3.23 they are too close to wing like that. Besides he already has lots of good information about what few ratios it could have been and the SPID codes to double check.
 
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