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I'm having an awfully hard time deciding between 4.10 or 4.30 gears. Car will be daily driven and see track time a few times a month. Not too worried about gas mileage. Are 4.30s too much?
 

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If it will be daily driven, 4.10s would be the absolute max I would go, and honestly I would consider stepping back to 3.73s, especially if you do any highway driving at all. Before doing any gear swap, drive around with OD locked out for a few days. That will give you similar cruising rpms as 4.10s.
 

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I have 4.10 gears still in the box I've been meaning to install in my car. From my research 4.10's is pretty ideal for street driving. 4.30's may be a bit much for a daily driver. It would be a good idea to put in an aluminum driveshaft and rear lube mod on the trans when you go into the 4's for gears.
 

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I think it really depends on where you commute daily. If you are in an urban/suburban setting or in the twisty hills, 4.30s would be just fine. If you are on the open highway at highway speeds very much, I would have to say 4.10s.

What distance is your typical daily drive and at what speed?
 

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Discussion Starter #6
20 miles a day on the highway going 55 to work and back. Plus whatever putting around town I do.
 

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Discussion Starter #8
With 4.30s at 70 MPH the.engine would.be spinning somewhere around 2700ish in 4th. With 4.10s it would be at 2500. Not a huge difference imo.
 

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3.73's would be my go to gear for a daily driver. I wouldn't go higher than 4.10, but as tbirdtess mentioned 3.90's are a good in-between.

Speaking from experience, switching from 3.73's to 4.10's helped my track times but my top end is now very limited. 4.10's are not a highway friendly gear at all and 4.30's, IMHO, are a track only gear.
 

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Speed of course. You sacrifice a lot of top end speed with lower (numerically higher) gears because they push the RPMs up so much faster you end up running into your engine redline. My car tops out around 130 MPH in 3rd gear at my redline of 7,000 RPM with the 4.10's. At the stock redline of 5,500 RPM top end would be around 110 MPH or so. I learned the hard way not to to do top speed runs in OD because the OD band burns out.

I don't have the spreadsheet handy, but GM sent me an excel spreadsheet that does all the calculations for various gear ratios and MPH at various RPM speeds.
 

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I would have no fear of 4.30s based on what you said. You'd be around 2150 rpms in 4th at 55 mph with stockish tires. ;)
But in the words of Sammy Hagar, I can't drive 55! Traffic around here is usually running around 80mph, and with 4.30s that puts you at 3100 vs 2700 with 3.73s. That makes a huge difference in terms of the comfort and noise level inside the car.
 

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I've driven both 3.73s and 4.10s for a number of years each, and ended up switching back to 3.73s. They make the car quieter and less busy. Plus, by switching to a shorter drag radial I really didn't lose anything at the track.
 

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time frame?

:wavey:

Hay, what's your time frame?

I have 4.10's in a 7.5" open dif. right up the road. (just over 200miles)
if you want to try them?

Tonawanda, ny 14150 - simson st.

:zbench:
 
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