case310350

have 1 97 3500 with gov and plate 11 mods. have had truck for 5 years and has been great. just recently, and when engine is warm, when I need power the boost will go up to 25 and then drop to 18 will not go above 20, the engine feels like its missing ,egts go to about 950. this happens on hills i have gone up in 5th no problems , and egt about 750, the same hill now have to drop to 3rd to get up. Not sure where to start, would this be a head gasket? turbo problem? fuel? I am 90% sure when engine is cold it runs fine. I use the truck for work, so need to fix before it gets worse.

wheelo90

sounds to me like a fuel issue, check filters, and lift pump. how well does it start in the mornings?