There are a number of small jobs you can do that will make it Look better and run better.
New vacuum lines - $20
Rebuild and clean fuel injectors - $40
Clean and remove rust from fuel rail - $5 and a Dremel tool and small wire cup brush or flat wire brush and a dab of POR15 Metal Ready.
Pressure test/Replace Vacuum Reservoir/Coffee Can - Free to test it - $5 to replace it (Junk yard) - $45 for a new one - Ebay
Clean and comb your radiator/Condenser - $12 for radiator comb kit or less.
Clean and remove any dirt/rust/crap under the hood
New TPS - Motocraft only
New IAC Valve - Motorcraft
Clean and remove any and all sludge from the PCV system. Clean any carbon buildup in the intake. Test tube brushes from amazon for the passages in the upper intake work great. Lots of Brake Kleen required. Cheap long handle stainless brushes from Harbor Freight for the runners and plenum. More Brake Kleen. Dont forget the pocket in the passenger valve cover where the PCV Valve attaches. Replace PCV Valve, PCV Hose, and clean out the actual fitting where it connects to the intake and the passage under it with the test tube brushes.
Clean all the black sludge from the throttle body and in the IAC Port on the throttle body using tooth brushes, throttle body cleaner, soft rags on coated surfaces.
Clean and paint anything and everything under the hood. Take small parts and brackets to be bead blasted clean. Then paint with high temp paint and clear coat.
clean all bolts with a wire wheel, chase all thread bores with bottoming taps and remove crud from thread bores.
Use Permadry Blue Gaskets
Check your harmonic Balanced and front timing cover seal. If theres a ridge cut into your balancer where the seal contacts it, get the felpro balancer sleeve that comes in the timing cover gasket kit and sleeve it, and replace the front timing cover seal.
From looking at your timing cover under the water pump, it looks like someone has been running regular tap water as coolant. I would thoroughly flush the cooling system multiple times to get all that rust and crap out of the block. Only use 50/50 premix or concentrate and distilled water to prevent further corrosion.
Clean all wiring. Strip the harness of all old tape, loom and soak the wiring and connectors in a 5 gallon bucket with dawn and water over night. Pull it out, clean all the wires, de-pin the connectors, clean up the terminals with scotch bright, pick the connector clean of grease and dirt with a tooth pick, gasket pick or other small pointy tools. Dry everything good. Get new loom, and new Fiber Tape to re-wrap it all.
Theres never a better time to clean out the A/C/Heater Box than when the engine is out. Open up the evaporator box, replace the rusted out bottom screws with stainless screws. Clean out the evaporator box. Check your evaporator, try to clean it out, if its too clogged up, it might be time to replace it and recharge the AC system. If you break into the ac system, replace all the o-rings on all the hoses, always replace the dryer after breaking the system seal. Remember replacing parts of the AC system reduces the amount of oil in the system. Oil may need to be added back to account for the oil trapped in each component. Proper oil in the AC system is crucial to performance. Too much or too little is bad.
Check everything for leaks. PS System especially. Theres no better time to upgrade to the Saginaw Steering pump using E series van parts from the junk yard. Use the bracket, pulley and bolts from the E series van. Take the Van Pump and Pressure hose to a parts store, use the old pump for a core for a rebuilt pump, use the HP hose to show the parts guy which hose you need. Get a new hose. I like NAPA the best for these components. Theres lots of writeups here about the swap. Its SIMPLE. If you have steering box play, change it NOW with a Red Head Steering gear if funds allow.