Gear Ration: Gear Ratio From 3.42 to 4.10 w/ new Posi Gear

[Ray..Ray]

I have just upgraded my gear ration from the stock 3.42 to 4.10, also replaced the stock clutch type Posi so I don't have to use friction based gear lube. I also added an additional leaf spring so the back end doesn't sag so much when loaded. ; )

I knew my speedometer would be off so my question now is that how do I go about reprogramming so the I can adjust for the new gears?


Thank You,


1999 Chevy Suburban K1500 LS
5.7L
108k miles

[mainechev]

Get the pcm tuned by a professional like Black Bear, Westers, Wheatley, or PCM for Less.