Sorry I didn't realise you were talking toys here.
well here are some basic stats.
86 toy went with IFS. I wheeled the piss outa my IFS. no real probs with like 200$ in lift and 35's.
When you get IFS in about 87-88 they threw in EFI fairly standard. You also get a slightly wider and more heavy duty rear axle and braking system. The width is the most noticable. Problems with the 1st gen 79-83 trucks (thats all I know) the front cab corners are always toast on the body mounts. The bed rails rust out. Tailgate usually is SOL to.
Probs with second Gen 84-88 Bed rots out right at a middle bed seam. The window regulators always strip out and need replacing. fenders are to close to the door and seem to get bent or kinked when they get snagged by the door.
probs with third gen 89-95? Head gaskets on the new V-6. Timing chain is now a belt and needs replacing about every 3years. Also heard of the rear R&P giving greif.
.
.
.
Wildyoats always gets rides.
Watch the paper.
1st or 2nd gen truck I usually find for 500 to 1500 depending whats wrong.
3rd gen gets to be about 3-5K but I don't look much.
Good luck and if you want me to keep an eye out I can. If there are other "spacifics" you want or need someone to go look at a truck let me know.