1995 extended cab 4x4..injectors, air cleaner, gov springs, del valves, no.8 cam plate...just took it two weeks to a local diesel shop. he is very good. he advanced the timing . now the milage went from 18 city to 15 ish....no load and driving normal...thanks in advance..........

 

The larger delivery valves and injectors affect mileage. With all that new power on hand you are more likely to drive it harder which is probably the biggest hit on your mileage. if you drove it exactly the same as before you would probably get similar mileage, but who does?!

 

It's very hard to resist the temptation to use the new power, it will drop your mpgs considerably. .
Taping an egg to the fuel pedal will solve your problem

 

What DV did you put in??Is it smoking heavy now??You may have to thighten up your AFC...