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Discussion Starter #1
I have been going back and forth on what ring gear I wanted to install in my '81. I went back and forth between 3.08 and 3.23. Well, it turns out after an exhaustive nationwide rear axle search, NEITHER complete axle's were to be found. So my only choice at this point is to work with what I currently have. Which is....I think, the factory 7.5 rear end, that's been completely rebuilt and a 4.10 gear installed. My research shows the highest, or numerically lowest gear I can install in this rear end, is the 3.23. Phew....OK, done!!!

Now all I need to do is order a Ring and Pinion, and a Master Install kit......and oh yeah, FIND SOMEONE TO INSTALL IT!!!
So, I am open to suggestions. Does anyone have a recommendation for a Central Virginia, or thereabouts, shop or "Guy" they know, who can do my rear end? I'm willing to pay a fair price, but it's a specialty. Both the shops I use said they don't set up rear ends. Do you guys have a recommendation for a gear installer in Central Virginia?
I'm open to ideas???
Thanks.
 

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rear ends are a specialty, no doubt. have you checked with an 4x4 truck shops or shop that balances driveshafts?

as for the differential carrier, shoot me a PM with your phone #
 

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Did neither of the shops you regularly use have a recommendation? That's always my second question when the answer to the first question is "We don't do that."
Is there a race track in your area? Talk to some of the guys in the pits about who sets up rear gears.
 

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Discussion Starter #4
Did neither of the shops you regularly use have a recommendation? That's always my second question when the answer to the first question is "We don't do that."
Is there a race track in your area? Talk to some of the guys in the pits about who sets up rear gears.
My favorite shop did in fact recommend a guy. The other was no help. I have contacted the "Guy" and we are talking, but he's a one man crew, and is at least two weeks booked up. But he is my current best hope.

Is there a Race Track........I live in Richmond Virginia!!! We invented Race Tracks, LOL Well, sorta'. ;)
I never thought about that. But that is an excellent idea, as I literally live less than ten minutes from Richmond Raceway. I will research chassis shops and race car builders. That might turn up some excellent leads.
Thank you.
 

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My '84 had a 7.5 in with a 2:41 in it. I searched for the same thing a found the largest that could have been put in it was a 3:08, Anything higher and i would have had to go with a 8.5 in. so right now i have an Auburn Pos. 3:08 in my 7.5. Hope this helps
 

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Discussion Starter #6
My '84 had a 7.5 in with a 2:41 in it. I searched for the same thing a found the largest that could have been put in it was a 3:08, Anything higher and i would have had to go with a 8.5 in. so right now i have an Auburn Pos. 3:08 in my 7.5. Hope this helps
A couple questions, if I may.
How do you like the 3.08 gear. Still pretty hy-way friendly? How's the off the line punch?
Did you have a shop set up your Auburn and gear? If so, what did you pay?
Inquiring minds want to know!!! LOL
 

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it was a 15 yr project and within the last few weeks i am just finishing it up so no Reg. or plates yet...but took it out on the side street last week for the first time and came back with a hurting snapped neck lol. my application is a LT1 w/4L60E(w/shift kit). Right now, with this short road experience, it seemed like i had high torque. For my set up other people here on ECC and LS1/LT1 said that 3:23 or higher would be a good selection,but that would have led me into a 8.5 in rearend. an 8.5 out of a G-body Buick grand national would be a good choice. At the time, (about 2 1/2 yrs ago) when i was at that stage of my off frame rebuild, that was what i had to work with and trying to do the best with the $$$ available. i followed the Auburn instructions and did the work myself. i think the gears were around $400.00
 

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Discussion Starter #8
i followed the Auburn instructions and did the work myself.
Wow! Kudos to you. I just don't have the nerve to try to set one up myself. I will be doing the 3.23 with no overdrive. My calculators say I can run all the way up to 70 and still be below 3 thousand RPM.
And thanks for the great reply!
 

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OK hawaii, you found out the 4L60E has a really steep 1st gear. (y) with that LT1/4L60E and 3.43 rear gear it's easy to spin the tires. And with a shift kit in the trans it will get a solid chirp from the tires grabbing 2nd.
 

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OK hawaii, you found out the 4L60E has a really steep 1st gear. (y) with that LT1/4L60E and 3.43 rear gear it's easy to spin the tires. And with a shift kit in the trans it will get a solid chirp from the tires grabbing 2nd.
hi Greywolf,
I'm probably beating the dead horse with this question, but once i get out on the highway and do normal driving. what would i expect to see running this 3:08 as far as RPM's: @ 50 MPH,@60 and @ 70? And the same for the 3:43 gears? Thanks!
 

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A couple questions, if I may.
How do you like the 3.08 gear. Still pretty hy-way friendly? How's the off the line punch?
Did you have a shop set up your Auburn and gear? If so, what did you pay?
Inquiring minds want to know!!! LOL
3.08 gears were good, but I had a TH200-4R trans.
 
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It's not only the gear ratio, but also the tire diameter that affects your rpm/mph. With my 3.43 rear end and 28" tires it turns about 2200rpm @ 60mph.
 

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Discussion Starter #13
It's not only the gear ratio, but also the tire diameter that affects your rpm/mph. With my 3.43 rear end and 28" tires it turns about 2200rpm @ 60mph.
Agreed. My tires are just about 26 inches tall. A hair shorter, but close enough to call them 26 for calculation purposes. If I was never running over 60, I'd just leave the 4.10's in and deal with it. The problem is, I almost never run UNDER 70. And even with 3.23, I'm right at the 3K RPM point as soon as I cross 70 MPH. I know 3.08 would be the ideal compromise for my setup, but the highest (numerically lowest) gear that will fit in my current 4.10 carrier is 3.23. Or I need to add a carrier to the price tag. I know it's "just money", and I should just do it all the way I want, but I have a host of other things that need attention, not to mention she just lost a lifter. Or I think she did. She's got a terrible lifter tick, and that takes precedence over everything.....for now. I've been searching for a stock axle to swap in, but that has yielded no results thus far. So rebuilding the current rear end looks like my only option. And a 3.23 will be the most cost effective. :)
 

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hi Greywolf,
I'm probably beating the dead horse with this question, but once i get out on the highway and do normal driving. what would i expect to see running this 3:08 as far as RPM's: @ 50 MPH,@60 and @ 70? And the same for the 3:43 gears? Thanks!
So here's what I get from just looking at the car's speedometer and tach
50mph = 1900rpm
60mph = 2200rpm
70mph = 2500rpm
I can tell you the car is perfectly happy running at 75 all afternoon, like to fort worth for the 60th anniversary get together.
 
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