I have 24" rims on my Tahoe. The stock 3:73's are getting swapped. I have a set of OEM 4:10's in the garage with an Eaton LSD. Am I going to notice a change with gear swap? I know most say on stock tires 3:73 to 4:10 is not much, but when you’re runnin' tires that are 8 sizes bigger than stock, maybe it will be noticeable. Or should I send them back for some 4:56's? It is a daily driver and the big wheels may come off one day. Opinions?

 

If You Are Looking For Performance Go With The 4:56. Cause If You Think About It 3:73 To 4:10 Is Not A Big Jump. Probably Wont Even Notice It.
If I Was In Your Shoes I Would Go With 4:56 With That Big Of A Wheel Tire Combo. Hope I Have Been A Help

Seth

 

I'm trying to get back the stock feel. The take off is a little slower on the 24's than on the stock 16's of course. I figured going up a gear size would level the field so to speak. If I go 4:56, and then go back to stock tires, that may be a little nuts. Does anybody know of a calculator where you enter tire size and current gear ratio and it estimates you your new gear ratio?

 

ttt for me.
I might be ordering the 4:56's tomorrow so I'm looking for more opinions or experinced people to chime in.

 

What is the overall diameter (OD) on your tires? Although I have 20's, my OD is the same as my stock tires....32". Going from 3.73's to 4.10's, I noticed a significant difference in off-the-line response, such that there is zero hesitation or lag getting going.

If it weren't for the gas hit, I'd be 100% pleased with my swap. 4.56's were not even in the running....no way I'd want to be spinning 3000 RPM's on the freeway at speed.

 

From the ground to the top of the tire is 32" (305/35/24) if I remember correctly. I was worried about freeway speeds as well. I don't want to shift into overdrive and be at 2000+ rpm. I guess with our heavy *** trucks the 3:73 to 4:10 swap is more noticeable than the RCSB guys. The stock tires were about 30" from the ground to the top of the tire (265/70/16) so not too big of a difference.

 

From the calcs I have done a 29" tall tire with 3.73s is almost exactly the same as a 32" tall tire with 4.10s.

A 32" tall tire with 4.56s is about the same as a 29" tall tire with 4.10s. LOL

I used the calcs at SmokeEMup.com

 

With 3.73's and 32" tires like you, I was running 2000 RPM's at 70 mph, the outside edge of our motor's efficiency with regards to gas mileage (1800-2000 is the sweet spot with LS1's with regards to mileage). Even though I would often run at 75 MPH, I was still getting 19 MPG, even with the Radix.

Once I swapped out to 4.10's, all those RPM's jumped 10%. So, instead of running at 2000 RPM's at 70 MPH, I am now running 2200 RPM's, with a corresponding drop to 17 MPG. And those times when I have to go 80 MPH to stay up with traffic, instead of running at 2250 RPM's, I am now running at 2500 RPM's. At that point, I am getting 15-16 MPG.

If you want that get-up-and-go that you had with the original tires, 4.10's will do you just fine, I can vouch for that. With 4.56's, you'll get some additional oomph, but it will come at a cost - you'll be running 2400 RPM's at 70 MPH, 2600 at 75 MPH, and 2750 at 80 MPH. I'd hate to see your gas mileage at that point.

Check out this calculator - just plug in your tire size, desired drive ratio (they call it final drive ratio but it is actually the rear end gears, two different things), 4L60/65 gearing (3.06, 1.63, 1, .70), our 6000 RPM redline, and use 50 RPM increments.

 

3 points, first, for a 32" tall tire my personal preference would be 4.10's, however, lots of people like 4.56's as well.

Second, I have found the factory Tach in my truck to be anwhere from 100-200rpm off of actual engine rpm as monitored through an auxillary gauge and HPTuners software.

Naked- Maybe when you were seeing 19mpg you were actually in this efficiency range you speak of, rather than on its edge.

Third, I would use data logging software to actually track engine rpm over the dash Tach, IMO and if available, that would be a truer measuring stick.

also, if anyone else cares to test this, please do, and report back.

 

Alright. you guys convinced me to stay with 4:10's. I'm already used to putting $50 a week in this thing so $55 wouldn't have made much difference with the 4:56. The highway rpm is what sold me. I don't think I could listen to the exhaust drone in OD at 2200+ rpm. I guess if I really want to feel the power I will just have to reduce or remove the bling bling. I still want to run the 24's at the track to see what my true street time is. Thanks for all the inputs.