Some trimming is required to clear the cab
Here you can see the fender bulge and why nearly 1/2" had to be removed across the top section. The flares are smaller than the wheel well. Below the gas door , in the wheel well you can see the section that won't touch (this was the worst fitting place of the four). The rear corner is closer but still too tight to touch. I filled the gap with silicone from the inside.
Quite a bit of cutting was required to get the recess to fit. The fronts fit pretty good right out of the box.
You will need:
The front flares for '95 -up S-10 part# 49014 . These front flares will fit easy, and nice with very minor work.
The problem lies in the rear flares, The '95-up S-10 part# 49015 flares do have enough material to be cut down to fit.
It would be better if you could find rear flares for a '96-up Isuzu pickup. Bushwacker doesn't list them on their website though. Might be worth checking other manufacturers too.
If you really want flares and feel comfortable with grinding a set of new S-10 rear flares, go for it ...It can be done! The complete set should run less than $350
What I did: You will have to first remove the stock rear flares and store or sell them. A contoured strip along the top of the new flare has to be cut to match the profile (about 1/2") and the bodyline recess is less pronounced requiring a pretty good trimming. I used a compass (cheap set just like the ones we all had in school) Taped up the sharp end (so it wouldn't scratch the paint) and used a silver pencil (welders pencil) for marking the flare.
Hold it, the flare, up against the pickup squared vertically, set the compass to the widest gapped point and trace the contour. Keep the compass at 90* to the flare surface. Then I used a thin cutoff wheel on my 4" grinder (a jig saw could be used but use masking tape to prevent scratching the flare) to cut 1/4" from the mark, smoothed the edges with a knife and file and refit and re-marked the lines. After about three times of doing this the gaps closed and it started fitting pretty good.
The welting that comes with them will cover minor imperfections in fit (1/8" or so) The bottom portion of the front of the flare extends into the gap between the cab and bed and needs to be trimmed a little so it doesn't rub the cab.
Plan on it taking a weekend to do and take your time, trimming a little at a time. The flare is not big enough to fit the wheel well so it will have two areas on the inner lip that will not touch. I mounted the lower portion with two screws about 6" apart and the top with three spaced about the same. Then filled the spaces in the corners of the well where the surfaces (lips) didn't touch with silicone.
Most people will never notice the little things that give up that they were not made for this truck. It has been a long time since I did this, hope I got it right...sheez it is starting to sound bad, huh?
Worst case scenario you will totally ruin a set of rear flares and be out $175. It is not for the faint of heart, but you don't have to be a body and fender expert either.