I have a 95 peterbilt 379 with a 5ek it currently has a 500 file in it. The truck has 370 rears and a 15 speed sitting on tall rubber. The truck seems to fall on its face when going up a small hill. Even when pulling on flat ground it seems to struggle to get from 50 to 75 almost like it’s running out of fuel. You can stay in it as long as you want and the pyro won’t get over 750. I’ve changed fuel lines transfer pump ran the over head and I’m still having the same issue. It has around 90psi of fuel pressure at idle and over a 100psi at 1500rpm. It has a brand new cac and pulls about 38psi under hard pull. Doesn’t miss or have any blow by the truck seems to run really well until your trying to pass someone or cruise up a hill. A friend of mine has an identical truck engine rear ends and trans and it will run off and leave mine any suggestions?