There is a huge difference between a F150 and the 250/350. There is almost no difference between the 250 and 350. Both have a solid front axle, same engines, same transmissions, same frames. If you're gonna be plowing anything more than your own driveway, I'd go at least 250, because the independant front end on the F150 wasn't designed to carry that weight.
As far as the diesels, I wouldn't say the old 6.9's and early 7.3's (pre 1994) were junk. They did last forever, but they were indirect injected, non-Turbo, and kinda slow. The 7.3's (post 1994) were bombproof. I have a 1996, and a 1997. My 1997 has 325,000 miles on it. The 6.0's were the cause of this ongoing lawsuit with International Engine. I'm not a fan of that one. The 6.4's are an awesome motor too, but a $7000 option. The diesels do cost a little more to maintain, but in the long term, they do last much longer, have much more power, and take much more abuse. And as far as cold weather starting, NO LONGER AN ISSUE.
The bad side is, If you get a diesel, get rid of it before the warranty is up, (FORD CHEVY OR DODGE), because whatever does need repairs, you can't afford it, and working on it yourself is impossible for most of us. Just look under the hood. Don't even know what you're looking at. Glow plugs are 800 bucks on the older trucks, (did mine myself), injectors are around $300 a piece, and there's 8 of em. And should you launch a turbo, or the whole motor, though unlikely, that's a second mortgage.
Last edited by driver444; 02-28-2009 at 12:36 PM.