does anyone know if it is possible to take the barn doors off an old suburban and stick them on an 86 k5 blazer?

 

It'll require some fabrication, but the back of the vehicle should be quite similar. You might want to have both vehicles handy to be able to cut parts when necessary.

 

Its going to take some serious body work to get the doors to seal just right and also I think you will have to strengthen the areas were the hinges are going to mount to on the body so your doors don't end up sagging. Take lots of pictures and post them up and we can help navigate you in the right path if need be!!