Welcome to the 7.3l world don't let the high mileage scare you away from a 7.3l if they are very well maintained and have the service history these engines are capable of a million miles or more. My friend had 1.2 million miles on the original engine before her truck got totaled. I just recently, had to put my spare engine in mine which had 998,792 mi. on it still running great but, I was getting exhaust gasses into the coolant system so, I just went ahead and pulled the motor. Good Luck! with your new to you truck.I will have to Get and learn how to use an ohm meter
I hounded my kids when they started to drive about spares and changing a flat. Made them do the drill after I "arranged" a flat for them at an inopportune time. In late June I had a flat along the road with my 2012 F150, and realized I'd never had the spare down or ANYTHING! I was sweating bullets until I got it squared away, knowing I'd NEVER hear the end of it if the Mrs had to come fetch me...A small can of WD40 works wonders on a lot of things including that bolt.
Thanks for reminding me, I haven't pulled the spare down in 19 years. I just carry a plugging kit and a air compressor