Christi:
Please keep in mind, that the following is just my opinion,,,, nothing more. With that said.......
Find the tow rating on your truck. (contact the dealer, or Ford rep if need be, but you can probably find it at
www.Trailerlife.com). Knock 25% off of that. Now, stay UNDER that weight. (again,,, just my opinion). I believe you will find that you can tow that amount just fine.
You might want to stay out of overdrive, but I would play that by ear. If you find your engine bogs down, or the trans shifting in and out of 4th alot, I recomend keeping it out of overdrive. Keep in mind, that at lower rpm's, you are not pumping as much fluid through your cooler, (trans will run hotter), and everytime your trans shifts, it slips a little, (trans gets hotter still).
In general, OHC engines, (like yours), tend to make their power higher in their rpm range, than pushrod engines. Again,,,, in general,,,,, there's always execptions. Where some pushrod engines are running out of breath, a OHC engine is just getting it's second wind. While this tends to make them less than ideal for towing, (not as much low-end grunt), they are ok if you keep the revs up. This is where your 3:73 gears, and staying out of overdrive will help.
About you not having Ford's tow package, usually a tow package consists of items such as a good hitch, extra trans cooler, lower (higher in number) gears, trailer wiring, and sometimes bigger radiator and heavier shocks. (Again,,, usually). Most of which you are adding yourself. Again, check with your dealer or Ford, match, (or better) them, and again, I believe you will be ok.
You might not want to get into a possible gear change, (3:73's are not that bad without overdrive), and once again, staying under that 25% of your max tow rating, things should work out ok.
You mention your truck wearing out sooner,,,,, be sure to change your engine oil and filter every 3,000 miles. I would also recomend changing your trans and differental fluids at least every 12,000 miles, or once a year.
Hope that helps
Mack