86 is different from 87-96.

Since he is in CALI he needs a CARB compliant cat which is why they are so much more expensive than some of you may remember getting them for. So yeah you need to either buy a carb compliant cat or get one thats not CARB compliant shipped to someone not in Cali and then to you(It's illegal don't do it(disclaimer)), but then you CANNOT get it smogged without a CARB compliant cat, they look for the CARB numbers on the cat and run them to make sure it is legal in Cali and if you don't have it then you are SOL and fail.

Any CARB compliant cat will be fine, find the cheapest one that has the same size exhaust tubing and made for our trucks and you will be fine.