97 Silverado 5.0 hesitates upon hard acceleration

I have a 97 Silverado 2wd 1/2 ton 5.0 liter automatic 157,000 miles that lately when accelerating hard at about 3500 rpms will hesitate/studder and the battery light on the dash flashes. If you back off the truck runs fine. It was tuned up less than 10k ago, new battery and alternator three years ago, new fuel filter two weeks ago, new fuel pump three years ago. It has also become a little harder to start in the mornings?