92 1 ton diesel

[2Lane racer]

Hello all. I received this truck from my father recently. He had a jasper rebuilt moter put in it a couple of years ago and it only has 8,000 miles on the moter and 160,000 on the truck now.

 

What are the first things to do to give it more power? Can I get a larger turbo for this? it has a large exhaust pipe maybe 3.5 inch from the y collector back. does this need to be larger? what companies have performance products for this old truck?

 

Thanks for any help.