New 4,88 gears, 35 tires. Recalibration of the speedo?

New gears (4.88), taller tires (35), 15 Tacoma Prerunner v6, 6 in lift.

Toyota tells me they cant fix the speedo. I looked at a few post and didn't see much that could help and most of the posts were old. Toyota tells that they cant help, speedo shop here in Scottsdale AZ said no, the box module's that were in the posts I can seam to find for a Tacoma.
For my sanity I cleanly want this fix, don't care how much its off, just fix and accurate. I don't know much about how this could throw off other things in the truck since the gears and tires are now on the truck. I am aware the lift, taller tires are going to give me bad gas mileage, however, I didn't foresee it getting worst gas mileage then my old big block Chevy. I have this meter that plugs in to the obd2 and its showing 10mpg going what might be 65mph, driving it like there's an egg under the gas pedal. I have worries that since everything has been changed, other issues might arise.
1, Is there a not too complicated solution to fix the speedo?
2, What other hidden issue have other encountered after gears, larger tires and a lift?

Thanks for all input.

 

I believe hyper tech makes a recalibration kit, but seriously that’s part of lifting a truck, everything that has to do with speed calibration or some sort of speed sensor will be off, i.e. abs system etc. gonna be down on power, towing shit even worse gas mileage, don’t expect more than 14-15mpg with 35s.

 

On my 2001 Tundra I had the same setup, 4.88 with 35s and used TruSpeed Speedo Recalibrator, which got it dead on back to stock calibrations, but a quick search for that unit didnt bring much up so that company might be gone. But those speedometer recalibrators are definitely out there. Check out Hypertech.

And yes, once I lifted 6" there were all kinds of issues, but it just comes with the territory.

 

There is a thread with a cheaper solution than hypertech I think.

 

Dakota Digital
https://www.tacomaworld.com/threads/my-dakota-digital-sgi-5e-install-speedometer-calibration.560236/