I'm starting to consider selling my 1999 F-150 and upgrade to a F-250 or F-350. I would love to get a F-350 ext. cab short bed PSD 4x4, but they are looking too expensive with the right miles. Are there any major things I should look for when looking at these trucks? What are the problem areas? Currently I can get a good deal on a 1999 F-250 Ext. Cab short bed V10 4x4 with 128,000 miles.