i am looking into upgradeing my battery to a yellow top optima battery and run an upgraded after market alternator my anut was telling me to do that i have to send out my computer thats in my 98 blazer to gm to have it flashed and reprogramed but from others i hear i dont have to do that so now i dont know what to think so any help would be great

 

From what I've gathered, a bigger alternator should just be plug and play. I don't see why the computer would have to be reflashed as I don't think the ECM controls the alternator output