2wd 5.3L on 30" 20's 3.42s 4L60e
full bolt ons, milled .03 862, 210/218 116lsa tq cam dyno tuned 336rwtq before cam no cam dynos

truck gets around 23 highway at 70-75mph

planing on putting a posi in. Now would be the time to change gears

The truck makes a ton of tq and accelerates pretty fast under 1500 rpms

Was thinking with this much tq 3.23s shouldn't make it bog/lug and would give 1-2 mpgs better. What do yall think

It's a mild build dd doesnt hardly tow

 

If I was pulling 23 mpg I would be jumping up and down with joy. With 20" rims and 30" tires I'm not sure you would get any benefit from switching down to 3.23s, might make it lug too much.

 

Unless you live in the highway, driving over 75mph all the time on flat ground and never hit the streets in the city, stay with what you have.

 

What he said^^^^^ I hated the 3.23's in my crew even with the 6.0 they sucked. Turbo only gears in my book. Keep your 3.42's and be happy

 

It will lug. My truck feels like it lugs with 3.42s. If you are getting 23 you can't expect any improvement no how no way unless you swap to a 5speed.

 

Sold on keeping the 3.42s b/c the 6.0 makes some TQ and if that bogs with 3.23s then this lil 5.3 will to

I really want 3.73s but do mostly highway driving so these would probably drop my fuel millage down to 19-20

I wish someone would invent a dual gear system. have 4.10s for around town push a button for 3.23s on the highway < cool idea somebody steal it haha

 

Do yall think 3.55s would pull harder or hurt mpgs?

 

Maybe if I went back to stock 16's and 28" tires??? but then it would look as clean

When I put these 20's on I had a CAI and exhaust. It dramatically slowed the truck down

 

If your getting 23mpg I would not even be complaining or worrying about it.. 23's are a **** gear..

 

You are running at max efficiency as it is now. Swapping to lighter wheels would help a tiny bit your 30" tires are a great size tho.