Congrats...they are solid trucks and the 4.7L is a gem of an engine IMO.
I kept mine for my son to drive as well.
Hmmm...well seeing it has some years on it, there could be several issues needing addressing but can't think of anything that might not have been done by now.
Early on there was a recall on the balljoints. Factory were riveted on, replacements were bolt on.
Blower fan resistor failed early, was replaced with updated part that solved that issue.
Engine likes copper plugs...no need to mess with platinum or any other type.
Make sure only ATF+4 type fluid is used in transmission and steering.
Rear end is sensitive to oil level, if it drops at all pinion bearing is not being lubed and will fail quickly. Common for pinion seal to weep or leak, so check and check oil level in diff.
Transmission solenoid block was updated in 2003 and can be easily retrofitted to your transmission with a kit IF you experience any shift issues. Typically if solenoid block is going bad trans will go into limp mode which means its locked in 2nd gear.
2001 came with the 45RFE trans, 4-speed with 2 kickdown gears, thus the "5" in 45RFE. You can change the transmission ECU to the later 545RFE which turns the trans into a 5-speed. Basically you gain an overdrive gear. If you live in flatlands it is a nice upgrade and you will gain 1-2 mpg. If you live in hilly area, not worth it.
I've put 355,000 on mine, so probably have run into most of the issues you might come across.
