I had a bit of an emergency today and was really hauling *** to get home. First I know GM fuel gauges arent the most accurate so maybe I was running out of gas . It showed that I was almost out 1/16th of a tank. Anyways, I was hauling *** at full throttle and all of a sudden the truck feels like I let of the gas and then goes again. I heard a squeek from the engine like the belt slipped or something. This has never happened before. I havent retuned since adding headers, meth, and smaller 3.12 pulley. I was going to put it off until I got the cam. Maybe Im too rich when the meth fully hits?? Maybe bad belt slip from the smaller pulley???

 

my first guess would be out of fuel. i have the twin intank set up, i have sucked air at 1/4 tank before. the stock set up is better for not sucking air but will still run out if you are on it for long enough with low fuel.

 

Does your truck still have the speed limiter on it. That sounds what was happening.

 

I think you are right. I was also low on meth so maybe I was getting some knock too. I filled up (both) and didnt have any problems after.
Thanks, it freaked me out a bit.