5.3 turbo plus 4l80e what gears?

[Custom 68]

Hi all, Just looking for a little input. I have had the 5.3 in my truck for about 11 years now. about 5 years ago I did the turbo, I had the 4l60 with 3.73 gears for a short time with that but the converter didn't like the turbo so I swapped to a T56 I had and added 4.11 gears with the double overdrive.

I am now on the final (hopefully) trans with a built 4l80. I need a gear change. Any thoughts? I could go back to the 3.73 but that doesn't offer much from where I am. I need to confirm which carrier I have to make sure what gearing I can support as I don't want to change that. the truck 12 bolt has factory 3.08 gears but there maybe others that can be found.
Any thoughts? I do like to drive this. My last long trip was tough with the 4.11 and the 4l80 but I was in a time crunch and couldn't make the change.
thanks
Dave

[DLW]

With your street turbo setup, I would look at something in the 3.23 or 3.42 gears. Turbo's like load and lower numerical gears help. With high numerical gears RPM can build fast not putting as much load. Plus you cruise the freeway at a nice low RPM. A lot of determining factors go into it including tire size, converter slip, weight, etc..

[Custom 68]

Thanks for the input and that is what I had heard as well. I will eventually swap just looking for any input before I decide.
The converter is a 2400 billet converter and my current tire size is about 29.25 tall. I have weighed my truck but don't remember or have the numbers in front of me. I have not lightened it up infact since I like to take it on long trips I have AC, stereo and a bed cover I thought it was around 3900 pounds but that may be a little light.
the turbo is a T70 so it is not huge and spools very very quickly. the HP at the rear tires is around 480. It is not my daily driver but I just returned from a 1300 mile trip to cruisin the coast in it.

[Hart_Rod]

I was just under 4K lbs with my 6.2/6L80/Magnacharger/AC, so you are probably close on the weight you listed. I think the 3.42 will probable be a good choice with the height of your tires.

[DLW]

I agree with Hart_Rod, with that tire height a 3.42 gear would be good.

Not sure what gear Hart_Rod runs in his car, but with the 6L80 and his setup, a 3.42 or 3.23 would be nice too I think..

[Hart_Rod]

Originally Posted by DLW

I agree with Hart_Rod, with that tire height a 3.42 gear would be good.

Not sure what gear Hart_Rod runs in his car, but with the 6L80 and his setup, a 3.42 or 3.23 would be nice too I think..

I was running 4.11s with a 31" tall tire and absolutely loved it! 2200 RPM cruising at 80 mph...

[Custom 68]

Thanks guys for pitching in on this. I liked the 4.11 with my T56 it was a great ratio however now it is not... Ha. Anyway It looks like I am limited to the 3.42 ratio with the 12 bolt rear.
Dave

[Heavymetl]

Turbo 5.3 here.

I've got a 9" with 3.25, and IMO it works really well. I've clocked a 1.62 60' leaving on a measly 3psi at 4100lbs. In other words, the turbo setup will make the torque to get it moving. For what it's worth, I've got a 2" hotside feeding a PT7675 turbo. Spool is quick and effective.

I'd certainly go on the higher as opposed to lower side. A 3.08 would be great IMO. Just be aware, if you do take it to the track with good tires, a clutch type posi unit will die quickly. I killed one on my second trip to the track, went with a detroit locker and good to go since for dozens of hits.

[Custom 68]

Thanks Heavy I know the 3.08 gears can be found and I believe I have an OEM set. Then it goes to the 3.42 range I have not found the availability the 9" do maybe I should look for one of those...
I do have an eaton clutch type rear. I only use street tires but your 1.62 is impressive.