well for starters 250lds couldnt be diesel, had ifs instead of straight axel, couldnt haul as much, had the body of a 150 had 7 lug instead of 8 lug wheels, and had a different frame. other than that im not sure. basically they arent even close to the same truck. especially the 97-98s
Pretty much. The F150/F250 LD are about 1500 lbs lighters on average, The 4x4 version in the F250LD is IFS, The F250 Superduty has a straight Axle 4x4. You had more engine options with the Superduty, You could get Diesel, V10, or 5.4. I think with the F250 LD you got the 5.4 v8 or the lesser displacement 4.6. No diesel. The truck looks like a F150, drives like an F150, but has a lot more payload. Oh, if you wanted a light duty truck back then and you wanted 3.73 gears, you had to get a F250 LD.
My 97 F-150 Supercab 2wd, 5.4, 3.55 rear end, automatic has an 8000 lb towing capacity, but the payload is only 1780 lbs.
The 97 F-250 LD Supercab, 2wd, 5.4, 3.73 rear end, automatic has an 8,600 lb towing capacity. Payload around 2900 lbs.
So yes, it was an in between truck. I don't think to many of them were made because the price difference in the F250 LD and a regular Super Duty was not that different.
And this goes to show you that Not all F250's and all f150's are the same. I just found out that my 97 f150 has the same transmission that Ford put behind the 97 F350 Powerstrokes. My bet is that yours does too.