Another fuel tank capacity question

I am planning to get new fuel tanks rather than clean and line my old ones (ends up costing about the same with a lot less work!)

I've searched a lot of places and can't accurately verify the tank capacities of my truck ('93 F250 7.3 IDI, reg. cab, long bed, 4WD) before ordering. Rock Auto has 19 and 18 gallon rear tanks, and 19, 17 AND 16 front (side) tanks!

Can anyone help? I think it should be 19 gal rear, 17 gal front but not sure.
thanks.

Long bed trucks had 19 gallon tanks front and rear. That being said I think the rear one listed as an 18 is interchangeable with the 19. Probally just a slightly different stamping. All trucks had a 19 gallon rear tank stock.

Thanks. So the rear is definitely a 19 gallon then. Got it in the shopping cart.

Are you sure about the front tank being 19 on a diesel though? Will the 17 also fit? Rock Auto says the 16 is for "short wheelbase" which I assume is for a reg cab short bed and not my truck...

You may also want to upgrade your rear tank. http://www.rosewooddieselshop.com/DZLJIM/Ford/38gallonOBStank.htm

I did this with the same part(F26E) on my '93, and I'm pretty happy.
I did a couple things different than that post, though:
1. Didn't bother modifying the level sender. It hits empty at about 16-20 gallons left, due to the extra capacity.
2. Soldered on the copper tube for the pickup side of things to the end of the metal line, then put the pickup on the other side. One solder joint, no cutting, done.
3. Did not mess with the return line side. It's probably not 'right' as at low tank levels the return fuel will splash down, but it hasn't caused me any problems.
4. Didn't paint or prime it or anything. Mine was galvanized on the outside, and I was short on time anyway.

I also did this with the bed off, making access to the tanks and senders really easy. Removing the bed isn't hard at all, especially if you have an impact. The front two bolts can be a pain as they want to spin, so I have to cut a groove in the top with an angle grinder and make a "flat blade" screwdriver-type head, then use a piece of metal and vicegrip to keep it from turning.
(this also means the bolts can be re-used, vs cutting the head off).

Well, the spare tire IS missing, but I'd rather stay with a working stock setup. I don't drive long distances with heavy loads, and I like my gauges to tell the truth

So is the front "side mount" tank a 19 or 17? Even Spectra's web site shows both.
Rear looks like an F1G, and front (I think) is F14C. Truck is an XLT option if that matters.

16 and 17 gal front tank is for a shortbed truck. 19gal is what you need.

OK that's an F6C. Thanks.