I have a 91 sidekick with a aftermarket hard top.I would like a soft top for the summer time .I found a complete soft top BUT it said it is for a 95 to 98 .Will it fit my 91 sidekick?

Sort of.  You need to make sure you get all of the mounting hardware, and I mean all of it.  Including the little plastic bits on the corner and the bar across the back.  But the tub is the same between 89 and 98 so you can put it on there.

The 96 soft top is a bit nicer for staying on the rig, and you have the removable windows.  But the older tops are easier to take down for running with the top off.

remember, not all yeasr are the same, some you can open the tail gate with out taklng the top loose and some you cant> I think in 95 they made it so you can swing open the tail gate with out unsnapping the rear window.

That is why you need all of the mounting hardware. 

 Don't overlook the fact that the new style softops are $$$$ compared to the older style which you can get for around $150-180 new. Something else to keep in mind...

i got a rampage brand soft top from ebay for 200 for my 97, its pretty good quality so far.  tinted zip out windows and a good fit, free shipping too.....

mike