Does anyone know how long do decals last in storage? I have a set of 82 indy pace car door decals new in box & Iroc-Z door decals that I would like to sell,does the adhesive dry up in storage?

It all depends one the storage conditions : dry/wet, hot/cold.

I've seen people use NOS decals without a single problem, and others that couldn't even apply them.

Most decals are designed to have a shelf life of 5-8 years. The adhesive loses it's ability to stick. I bought 82 Pace Car windshield decals years ago and applied them to my car. They looked perfect for 24 hours!! I applied them before a World of Wheels car show, dropped the car off, came back the next day after work and all of the edges were lifting off the glass. I immediately removed them from the car.

Welcome to the site. I'd maybe install one and see how it holds up.