Not really sure how to explain this one. I have a 94 K1500 4x4 350 TBI automatic. Has about 280k miles on it and still runs just fine until you really give it some gas. When I first got the truck, sitting in park if you stomped it the motor would get up to maybe 2k rpm then act like it had launch control or something and would just bounce at 2k snapping and popping. It came out of it for a while but its back to doing it whenever you give it a lil too much gas going down the road. The whole truck shakes and the motor snaps and pops. I replaced the plugs, coil, wires, cap/rotor air and fuel filter. Nothing has helped I figured maybe it was starving or choking out. I'm wondering if there could be an electrical issue as the temp gauge is almost as nuts as the tach cause one minute it will be running at like 110 then 260 then back to 150.
https://youtu.be/7uJp_0KwD2k
My dad was thinking maybe a stretched timing chain but as violent as that is, and it does this every time you accelerate unless you practically let it idle up to speed. I would think it would have jumped timing or something by now but it runs near mint normally just idling or cruising around.