LS 408 Supercharged Differential Gear Choice, 3.73 or 4.10?

[Biggerdogg01]

Hi Everyone,

I am currently building a LS 408, Whipple Supercharged engine for my 2017 Silverad0 2500hd 6.0l. I will not tow heavy load very often, and the truck is my daily driver....just wanting to have some fun. Currently the 10.5 differentials are geared at 4.10, but with the future increase in engine power, I feel the 4.10 gears will be a bit much for take off, as it will rev to fast? I am going to install an Eaton Trutrac assembly in the rear, but wanted your EXPERT opinions on the gears? Advice appreciated.

 

 

[George Dieber]

I SC my 2016 Silverado 2500. Your Gear ratio will be fine. You have other things to be concerned about (Traction Control, Torque Limiting). Get a HP tuner and be ready to learn. 

[Biggerdogg01]

Hi George,

 

This truck is already supercharged, I am building a 408 to go with it. It is tuned with HP Tuners.

 

Thanks

[Chebbyfan]

I don't know if this will help, since my truck is not SC or built.  I think the one major flaw I can find is the first to second gear ratio in the trans.  I had my truck tuned, and I rod it around once in a while, but burn outs and launches kinda suck with this truck.  ( I know its not built for 1/8 mile or 1/4 mile runs, but its mine and I drive it the way I want.)  When it shifts outta first doing a burnout, it falls flat on its face.  I don't now if you'd have to open up the transmission and change that ratio, or my tuner needs to do more work.............   I think your 4.10 gears will be fine, it'll definitely be really quick off the lights!!

[KARNUT]

I’ve owned or built plenty of high performance vehicles. Even my stock 02 Avalanche will lay down rubber ifs that’s my desire. Family members of mine that drag raced their trucks either went 4WD or tire and wheel combo with slicks. My nephew daily drove a 10 second diesel truck in the early 2000s. 4WD street tires. My brother an 11 second little red truck he bought new. It has wide slicks with highly modified rear suspension. I learned to ease into the throttle for traction. With the TQ you’re running a more Highway gear will help with street traction with street tires. Will spin harder if you break traction. I always preferred the weak link be traction. Learning right foot driving rather than breaking parts with hard hook ups.


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[cmysstailights]

I just did gears, 4:88 new carrier and all the goodies.  I tow heavy and 4:10 didnt cut it.  Truck feels more responsive, not as heavy.  I would stick with the 4:10, more gear mean motor n trans work less.  Especilly when towing.

[Randy Thomas]

On 12/20/2020 at 11:55 AM, cmysstailights said:

I just did gears, 4:88 new carrier and all the goodies.  I tow heavy and 4:10 didnt cut it.  Truck feels more responsive, not as heavy.  I would stick with the 4:10, more gear mean motor n trans work less.  Especilly when towing.

I am not towing but a couple more times, then my 5th wheel will be gone. I am building this for the street, daily driver. 

[cmysstailights]

I am not towing but a couple more times, then my 5th wheel will be gone. I am building this for the street, daily driver. 

I havent towed yet, but i will say this. The truck feels lighter and more responsive. Still waiting on a retune for a month now.

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[cooldude960]

I am very curious how the Whipple works for you? I am thinking about adding one to my 6.0.

 

Who did your tune? I have read that the tune from Whipple isn't the greatest and leaves the truck with surging issues. Did you have this problem?