Hi Dig - this is not meant to be a smart a** reply, but - we need more info!
7.3 seems like a lot of cubes, and '88 is getting up there in years. Just guessing here, but maybe engine/drivetrain is gettin' tired or perhaps the truck's undersized for what it's doing? (eg towing a b-i-g trailer with b-i-g equipment on it?)
Not bashin' on you , it's just that the more people know about your situation the more likely they can offer helpful information.
Gale Banks makes at least three different kits for your truck. Go to Ford-Diesel.com, they have a list of performance products from just about every manufacturer in North America. BTW you may want to consider the mileage on the (transmission in particular) truck. The 87-94.5 diesel has the weaker version of the 4spd auto. If you have the 5-spd you could look into a clutch upgrade by Luk. Good luck wich ever way you go.
the truck is 13 yrs old,the upgrades may exceed the value of the truck.Those turbo kits arent cheapIf the motor is tired(likely) than the mods will not perform as advertised.Maybe you need to get the truck to a good deisel shop,get an oil sample,and a compression test,let them go over it,they will tell you the condition of the engine,if the oil has fuel in it,you have a tired engine or a bad injector.If i were you,Id consider selling your truck as is to someone who doesnt pull,and upgrading to a newer direct injected factory turbo diesel.A 94 1/2 or newer Powerstroke diesel will outperform your old truck,and get much better econonmy.In the long run it might be cheaper than a turbo kit,and enivitebly a motor,and maybe a tranny.Good luck.
the truck has a new motor in it . we replaced it 3 years ago. but the truck has never had the power to pull a big load . we have a 24 ft gooseneck it will pull it but I want more POWER . I went looking for a new truck mainly a power stroke, but thought if i could change gear ratio or transmission I might spend less. we bought the truck about 4 years ago for 10500 (new motor, new oil cooler , new fly wheel assembly another $9000.00}got so much in it hate to sell it . NADA list it for at best $6000.00. so need to try some thing.
DIG'EM you may want to try the Banks stinger system . It will give you about 40hp and 40lbs of torque. From what I've been hearing about the Luk single mass flywheel at FD.com you may want to give them a try also.