Re-geared my 2019

Albert Palos · February 4

2 hours ago, Transient said:

Those tires would be called "Metric 35s." Since you like Rough Country, look into their catalog. They have a speedo calibration device. Plug it into your computer, run the install wizard, tell it your OE tire size and then your new tire size, and it'll write the code. You then take it to your truck, remove 1 plug under the drivers side dash, plug the RC wire harness into that port, insert plug you just remove into the RC harness, and then tuck the rest of the wires away. The entire process should take you less than an hour. I've been running the RC speedometer calibration device for over 2 years. No problems, yet (knock on wood).

Albert Palos · February 4

Yeah Thanks, I'm aware of the rough country speedometer calibrater as well. I just want some information where I can get someone who do Texas speed tune

Luckyfd1 · February 5

20 hours ago, Albert Palos said:

Appreciate the info Luckyfd1, I too have a 2019 Silverado 5.3l, but it's a RST, I Have Cognito upper control arms with 3.5 Rough Country coilovers and almost 35" in tires but not quite. I've been looking for some one to tune or calibrate the speedometer odometer to match tire size for better shift points. I've also am considering the hyper tech speedometer odometer calibration programmers but now that you mentioned the freeway issues, I'm glad I haven't pulled the trigger. Would you be willing to give me some info as to where you had the calibration done. And the cost. I'm in the L.A area 562 area code. Thanks

Absolutely. When I get the guy’s name or the company name that tuned to the truck I’ll post it on here. I want to be clear though. I’m not bashing Hyper Tech or edge products they just didn’t work for my specific application, which was the large jump in gears specifically the 4.56. I know from what I’ve been told the Hyper Tech and the edge work phenomenal for 3.73. And I was told by Hyper Tech that there’s works up to 4.10. The ease of installation for those products is something else. Very easy to install and I’m sure both are very great products.

Luckyfd1 · February 5

8 hours ago, Albert Palos said:

The hyper-tech was extremely easy to use and corrected my speedo! Unfortunately didn’t correct the gears…

Edited February 5 by Luckyfd1

Luckyfd1 · February 5

1 minute ago, Luckyfd1 said:

The long tube headers and the DOD delete I bought from Texas speed. The Whipple I bought from their website, but the same guy is also gonna tune those modifications, but I have to go to his shop to put it on the Dyno.

I had to fix this issue before I installed anything else because we know what the problem is and I didn’t want to add more components to the truck and then try to figure everything out that would’ve been an absolute nightmare

Edited February 5 by Luckyfd1

Luckyfd1 · February 5

10 hours ago, Transient said:

@Luckyfd1which transmission do you have in your truck? There were 3 available that year.

8L90 8 speed, i’m not sure if I can be more specific. That’s all I really know.

Albert Palos · February 5

36 minutes ago, Luckyfd1 said:

Absolutely. When I get the guy’s name or the company name that tuned to the truck I’ll post it on here. I want to be clear though. I’m not bashing Hyper Tech or edge products they just didn’t work for my specific application, which was the large jump in gears specifically the 4.56. I know from what I’ve been told the Hyper Tech and the edge work phenomenal for 3.73. And I was told by Hyper Tech that there’s works up to 4.10. The ease of installation for those products is something else. Very easy to install and I’m sure both are very great products.

Albert Palos · February 5

Thank you very much, appreciate it

BIGDOGx · February 5

Wow 4.56 are like drag racing gearing lmao.

How does a tall gear like that work with these 8 and 10 speed transmissions, is it basically shifting through gears like every second? I would think this would make for some annoying driving characteristics using a gear like that.

Luckyfd1 · February 6

9 hours ago, BIGDOGx said:

Wow 4.56 are like drag racing gearing lmao.

How does a tall gear like that work with these 8 and 10 speed transmissions, is it basically shifting through gears like every second? I would think this would make for some annoying driving characteristics using a gear like that.

So I drive the truck for a while on 3.23 and with the exception of steep grades on the freeway the truck drove fine. On the grades it would bounce between 8-7 so Keeping it in L7 with gear selection was the answer. If I remember 3.73 or close to it was basically putting it back to stock. I’m gonna run 37’s so I went a little lower. 4.88 is what was most commonly recommended. I don’t drive the truck very often but when I do it’s mostly freeway and I didn’t want the RPM’s to be high…

even with the 4.56 the truck drives amazing. Correcting the shift points is what the tune addresses. It shifts like normal.

Luckyfd1 · February 6

Lowering gears is misleading to most people. I’ve had gear changes where I felt like “why did I waste my money” but you’re totally right, the 8 and 10 speed with 35’s isn’t a real noticeable strain on the truck. However using the numbers it is extra wear on the trans. Putting it back to “stock” compensating for the tires is probably ideal for most people.

Edited February 6 by Luckyfd1

Albert Palos · February 6

The reason I'm looking for a speedometer odometer calibration is that having put almost 35"tires 295 70 r18 on my 5.3l with the 8l90 transmission, I would think it puts stress on the tranny and ECU thinks I'm going uphill. I've changed the transmission fluid twice,put PPE bypass valve and when I drive in city stop and go traffic for about 20min in L.A my transmission Temp gauge is at 180-190 so I kinda want to lower the transmission fluid temp. It's a preventative maintenance thing

Luckyfd1 · February 6

11 minutes ago, Albert Palos said:

The reason I'm looking for a speedometer odometer calibration is that having put almost 35"tires 295 70 r18 on my 5.3l with the 8l90 transmission, I would think it puts stress on the tranny and ECU thinks I'm going uphill. I've changed the transmission fluid twice,put PPE bypass valve and when I drive in city stop and go traffic for about 20min in L.A my transmission Temp gauge is at 180-190 so I kinda want to lower the transmission fluid temp. It's a preventative maintenance thing

So there’s a lot going on in that post. Forgive me if I’m taking you outta context…

The calibrator will correct your speedometer issue. The larger tires will put strain on your trans. How much is up for debate. The calibration won’t do anything for the transmission. The PPE basically allows your fluid to flow to the cooler immediately rather than waiting for a certain temp to open the “valve”. Chevy has an ideal temp range of 175-200. IMO if your within that range your good. I can’t remember exactly but I believe Chevy recommends the transmission fluid be changed every 30,000 miles? And if I’m not mistaken, they actually recommend a flush. Again, a flush versus dropping the pan is up for debate. You’re not changing a filter and with a flush, you can actually dislodge particles that can get stuck in the transmission causing issue. You don’t want your transmission operating temperature to fall below that range. Not counting environmental factors. But regular operating temperature.

asilverblazer · February 6

15 hours ago, Luckyfd1 said:

The larger tires will put strain on your trans... The calibration won’t do anything for the transmission.

And to clarify - changing the gear set will relieve that additional strain on the transmission...

...beware that doing so will cause the driveshaft to be turning faster; and the internet says there is a risk of gernading it at higher rotational speeds.

Luckyfd1 · February 7

On 2/6/2026 at 9:50 AM, asilverblazer said:

And to clarify - changing the gear set will relieve that additional strain on the transmission...

...beware that doing so will cause the driveshaft to be turning faster; and the internet says there is a risk of gernading it at higher rotational speeds.

In my case…going from 3.23 - 4.56, could that 4.56 be too much for the truck to handle? When I originally put an inline tuner on the truck (either one) the truck drove great but at higher speeds the drive shaft RPM was too high. Meaning you can “trick” the ECM/TCM but there’s nothing you can do about the drive shaft spin… what I’m getting at is the tune can’t do anything about the drive shaft RPM it only makes the computer interpret it differently. The truck is now limited to a lower top speed??? 85 is the new 112… ?

this was prior to the last tune that fixed my truck. I was curious why the inline models didn’t work.

does that make sense?

Edited February 7 by Luckyfd1