Mark,
Your 96 should use R134A refrigerant, most everything was changed over to R134A by 96. However, if you are ever in doubt about which refrigerant is used in an automotive dash air system, you can tell by looking at the charging ports. A R12 system will have the smaller outside threaded charging ports and a R134A system uses the inside threaded quick coupling type charging port. This change in charging port design was done to prevent cross contamination between the different design systems, and it even necessitated all the mechanics to have two sets of gauges, one for each system.
Gerald