Gears and no calibration

Hey everyone

I have 410 gears installed and my speedo is set for them. thing is i am going to sell my predator (had a custom tune with it for everything) before i get my kenne bell and tune this spring . Will there be any adverse effects from running the car without the tuner, just in stock tune? by the way the car is an 01 t3650. hopefully just my speed will be off? haha also how would this affect my odometer?

thanks