Freshening up a '97 F250 HD - 375K miles

So, this truck belongs to my fiancée and it was her daily driver up until last spring when she finally got a more reliable car and could take on a payment (Nissan Sentra). It has 374,000 miles on the odo and the previous owner claimed it was rebuilt around 170K ago or something but there are zero service records for it so I really have no idea what has been done to it since it was built 20 years ago...

It has a 5.8L EFI Windsor V8 (351W for the Ford folks), 4 speed E4OD auto trans, 2wd, 8ft bed used to haul whole round hay bales, single bench seat, does have A/C and a Sony head-unit with 4 working speakers surprisingly, manual roll up windows, and it drives. That's about all there is to it.

It was mostly retired in Dec 2015 when it was overheating but that has been solved with a coolant flush and refill X2 and it runs at a steady temp now (lots of gross gunk came out so I hear). I'd assume a new radiator and water pump would be a good idea but $$$ may be a factor and since it works anyway I'm just calling it good. It's been driven only a handful of times in the last year so we decided we should try and sell it for whatever it's worth. But in order to do so I want to make sure it's at least somewhat ready to sell.

So far it's had a coolant flush and refill, I just changed the oil 5.25 Qts 10W-30 & filter, new engine air filter (dusty roads majority of it's life), replaced the broken off interior door handle, vacuumed the crap out of it (under the seats was anybody's guess as to what was built up under there), wiped down the inside and power washed the outside in a general sense. It's not sparkly clean but at least it's not covered in mud/dirt everywhere.

I'm planning to do spark plugs and maybe new wires next and then list it up. It runs well enough but doesn't sound quite right, kinda raspy. I'll upload a video whenever my 1mbps connection gets it through. My guess is some kind of exhaust leak possibly or a bad gasket somewhere. Not sure since all my vehicles have always been fairly new or always ran well and I'm kinda new to the DIY stuff.

So TLDR: What would you guys recommend I check/replace that's somewhat easy for a noob to do before listing it for sale? Sure there could be some crazy horrible issues under the hood that I don't even know about but I doubt it'll sell for any more than 1K anyway so whoever buys it hopefully is a DIY truck guy or something. It's a good farm truck.

Also before it gets asked: All lights work, headlights, brights, tail lights and blinkers check out. Battery has a date stamp of 2013 on it from Walmart and the truck fires up every time without hesitation with a tad bit of gas pedal. It sat for 9 months and started right up when I moved it to my place. Also, brakes do work too, not bad tip in either for it's age.









374,100. Highest odo of anything I've personally driven I think. Her dad has a 7.3L Power Stroke Super Duty (2000 or so I think) with well over 300K maybe closer to 400K as well all original but I've yet to drive it, just taken a ride once.

Thanks guys! I'm more of a Toyota guy so working on an old Ford has been interesting. Amazing how easy some things are to get to though.

 

Plugs and wires is a good start. 351 is a pretty solid motor. It probably needs to get the head gone through to get tip top but if its running now and not smoking, the rings are probably fine if it's had an easy life. Exhaust manifold gasket is cheap and easy to do. New mufflers and cats probably too. Nothing fancy and its all bolt on. Probably clogged up cats and blown out muffler.