What Tom said, cubed:
Makes more economic sense - given it is a TRUCK, separate body & frame - to just buy a strategic few entire new panels in ignorant steel. Taiwan firms buy-up the old stamping dies and make these by the ton for inch-hoorance collision repair use. They fit near-as-dammit perfectly on (at least) GMC & MOPAR trucks, too. BTDTGTTS. Fords? Born ugly, so how would one even be able tell as to fit?
For the most part, they will be factory-fastener bolt-on or Lord special glass-bead epoxy plus rivet-on, perhaps a benefit from the odd strategic TiG touch.
The cheap ones expect a craftsman to salvage the inner panels. Do NOT Go there!
Buy the better ones that already have the inners welded-in. They ship with lower rosk of in-transit damage and fit better, too. Ask me HIKT? A loyal 1991 GMC Sonoma pranged in a collision as well as nibbled-on by rust.
First off, even though only plain steel, the parts are NEW, so even in primed-only, have a fresh start at the salt-belt corrosion life-cycle.
Secondly, you have the opportunity of improving corrosion-resistance as you go, because you can get AT all the innards, seams, laps joints, and welds as well as the outers.
Thirdly, you can do this whilst on sawhorses. Each panel can be laid to the best of SEVERAL angles for coating(s) to flow and get at and into critical corners and moisture traps.
Fourth - the truck is still "roadable as-is" whilst you prep all this.
Each section can then go into place when it is ready, primed-plus-plus, and a coat or two of your finish colour already on it. Get it "right" final-final spray is mostly clearcoat work.
Fifth - WHILE you have each quarter or side pulled to make the swap, you have easy access to treat the innards, the frame, supports, any other parts NOT being replaced.
Far better job at the end, and very much worth it at the price of new trucks, engine & running gear swaps as much easier as they can be.
3CW, but the damned "puters and wiring can be far the costlier show-stoppers than body rust.
I have had to resist the tempation to fit Stromberg carbs, hand choke, Scintilla Vertex magneto - and shed the entire lot of that half-vast electrical-wizardry s**t. I HAVE goen so far as DIY downdraft throttle-body Corvette FI and custom PROM onto a Vortex V6, and gotten BETTER emisisons figures than factory. Once. It wasn't a casual effort. Among other chalenges was bribing a GM staffer to get sight of the drawings for both. (GMC 90-degree V6 into '84 Jeep Wagoneer and the second owner is still enjoying running it, present-day).
But then... that was to 1984 Jeep // 1991 GMC engine specs, and tailpipe-tested, predating full-house onboard diagnostics tattle-tales.
Nowadays, you can't pass emissions for road use on the mere "principle" of it all, and I no longer need a "farm use only" pickup!
PS: Factory code primer, topcoat, and clearcoat paint and family, please. And/or the repair industry standbys.
Only. ELSE you are just creating a problem they solved arredy a very long time ago.
It ain't no $800 a gallon, either. Just look harder.
Even the 2005 Jaguar XJ8-L "mica slate metallic" for use on challenging (thermal movement..) aluminium body is only about $80/gallon concocted by the usual dominant supplier to the trade.
