Ordering new Truck, 3.23 vs 3.42

[buddyrda]

Hi All,

 

I currently in the process of ordering a new Sierra with the 5.3. I'm trying to decide between the 3.23 and the 3.42 rear end. Can anyone provide their thoughts based on personal experience? RPM range doesn't seem too much different between the two options. Is MPG much different between the two? Is acceleration much better with the 3.42? I won't be towing very often. Most of the time will just be using the bed (8FT).

 

Thanks in advance for your perspective.

[Z45]

If I am not mistaken, the 3.42 requires the rpo NHT Max Trailering Pkg..  

 

Edited March 11, 2022 by elcamino
typo

[asalinasz39]

From my personal experience...

 

I had a 17 5.3 8speed Silverado with 3.42 and I upgraded tire size to 33's....the truck was amazing no struggle whatsoever and the mpg drop was minimal

 

Now with my 19 5.3 8speed AT4...I have the 3.23 and upgraded to 34's lol....mpg's took a big hit...

 

Overall what I want to point out is if you have the option of going 10 speed and 3.42....then you score the best of both worlds. However, if the truck you want only has 10 speeds and 3.23 gears...you should be totally fine.

 

Also, if you plan to leave her stock...3.23's should be better for optimal gas mileage. 

[buddyrda]

It will be on stock tires 255/70R17, overall diameter 31.06"

 

[buddyrda]

51 minutes ago, elcamino said:

If I am not mistaken, the 3.42 requires the rpo NHT Max Trailering Pkg..  

 

Thanks elcamino this combination is not available on the 5.3 pro.

 

Thank you everyone for your input.

[Z45]

16 minutes ago, buddyrda said:

Thanks elcamino this combination is not available on the 5.3 pro.

 

Thank you everyone for your input.

On the pro you have select the 2.7L Turbo and it defaults to a 3.42 ratio.

 

Changing 3.42 rear axle ratio will also change the following:

Remove

• External engine oil cooler
• 170-amp alternator
• 7,100 lbs. GVWR
• 5.3L EcoTec3 V8 engine
• Automatic locking rear differential
• Not Equipped with Dynamic Fuel Management
• External auxiliary transmission oil cooler
• 3.23 rear axle ratio
• 10-speed automatic transmission

Add

• 7,000 lbs. GVWR
• 2.7L Turbo high-output engine
• 220-amp alternator

Price Change: -$3,440

[redwngr]

For 2022.5  (refresh) 'Pro' trim

 

GU6    Rear axle, 3.42 ratio
1 -  Included and only available with (L3B) 2.7L Turbo High-Output engine. 
 

GU5    Rear axle, 3.23 ratio
1 -  Included and only available with (L84) 5.3L EcoTec3 V8 engine. 

 

Not available on Pro trim

GT4    Rear axle, 3.73 ratio

NHT         Max Trailering Package, includes 9.76" rear axle, enhanced cooling radiator, revised shock tuning for increased control, heavier duty rear springs, increased RGAWR and (KW5) 220-amp alternator

[newdude]

19 hours ago, buddyrda said:

Thanks elcamino this combination is not available on the 5.3 pro.

 

Thank you everyone for your input.

 

 

Yea, on the Sierra Pro trim the 3.42 can only be paired with the 2.7 Turbo/8 speed.  The 5.3 is 3.23 and the 10 speed.  And the 5.3/10 speed with those gears is quick, especially in a regular cab 8ft box.  

Edited March 12, 2022 by newdude

[newdude]

20 hours ago, buddyrda said:

It will be on stock tires 255/70R17, overall diameter 31.06"

 

 

 

Just a suggestion.  I'd option it with the 265/70R17 that way you have a LOT more replacement options down the road when the truck needs tires.  255/70R17 has less options to choose from, and quite often tires in 265/70R17 run less $$$ than 255/70.

[TxTruckMan]

9 hours ago, newdude said:

 

 

Just a suggestion.  I'd option it with the 265/70R17 that way you have a LOT more replacement options down the road when the truck needs tires.  255/70R17 has less options to choose from, and quite often tires in 265/70R17 run less $$$ than 255/70.

Just because it came with one size tire doesn't mean you have to stay with that tire size.  You can put whatever size tires you want on it.