The ferd fuel injectors are cheap at my local JY and are easy to install and make a nice gain, probably be my first thing on most rigs depending on state of repair.

If your timing chain is wore out (most of them are)or your timing cover is leaking(most of them are) then stick in an adjustable double roller timing chain (I use a cloys) and advance it 4 degrees.

I see a lot of them where the fan clutch is real tight and they sound like an air plane, takes a ton of energy to move that much air, get an electric fan from autozone with the thermostat control and ditch the mechanical fan. Or you can get real cheap and pick just about any fan from the JY and wire it up with a relay to come on when the key comes on. Try to get the fan near as you can to the upper inlet where the temperature delta will be the highest.

Don't tell anyone but I run 0-20 oil in my trucks in the winter and 5-20 in the summer