Plugs, wires, air filter.
What else?

 

Coils and plenum?

 

Mass air flow sensor, vicious fan clutch, and valve cover gaskets

 

Tires and brakes to round it out?
......

 

If it ain't broke don't fix it, if it's sluggish try the 'Italian tune up', give it 'the beans' on the autoroute for half an hour, it's a make or break cure.

 

Check your fan belt, plugs, wires, clean throttle body, IAC, replace air filter, inspect flex hose to fender for holes, and change the oil & filter.

 

What's the Italian tune up?

 

OffroadFrance has some wise words. My "tune up" ended up being a complete engine rebuild. Ha! Where do you stop...

 

These guys are jerking you around.

Starting with plugs, wires and an air filter is just fine. But even before that, are there symptoms or codes you are intending to address with a tuneup?

When I learned to turn a wrench a tuneup, as I recall, meant new plugs (which in those days, 40+ years ago, had a much shorter service life), checking the distributor points (which no longer exist in modern cars), adjusting the idle advance timing with a dwell tach (which I still own just in case I ever get that '49 to '53 Chevy pickup I always wanted) and making all the requisite carburetor adjustments.

Today a tuneup is much more simple. Do not overcomplicate it.

 

The 'Italian tune up' is you give the truck or car a 'b@lls out' hard run using max throttle for 15 to 30 minutes and then see whether it's improved, as already said, it's a make or break scenario.