Help! I had a bad intake gasket so I spent today replacing it. When I filled the radiator it built up pressure after the truck ran for about 30 seconds. Now the truck lacks power for a minute then has power then loses it, back and forth. Idles at 600 rpm, sounds good at idlebut still has a lot of fog coming from the exhaust, cant tell if it was left from before or not. Was told that this model year has problems with the heads, in the 7 or 8 cylinder area and to start to look for a different engine. Any of you heard of this? Only had this truck about two months, hate to replace the motor so soon, it only has 150,000 miles on it.
Any comments would be a great help.

Thanks