Changing rear gears with l83 and 8l90e

[Cornholio7214]

I want to know how hard it would be to tune my trans if i changed my third member (3.73->4.86) and if id be better off just taking it somewhere. It's already tuned for the current gears and changing them screws with the shifting obviously. Also if anyone knows if id be better off putting in taller gears (3.00) for the 1/4 mile id love feedback. My hotrod is daily driven with a stock motor and trans besides tune and headers if that helps.
I would also really like to be able to swap the tunes whenever i change gears, it wouldnt be permanent. Im super new to this and i dont even know which thing to buy, whether it be the mpvi3 or anything else so input is greatly needed.

[blindsquirrel]

You can install VCM Suite in demo mode and see what's in there. Look through the Gen 5 forum and find some stock files to open and look through. Gear ratio and trans shift settings can all be changed.

After first installing make sure to do Edit > View > Advanced, otherwise 90% of the settings are hidden. 'Basic mode' needs to die in a fire.