Need help with understanding CA emissions

Hello all,
I am looking at a few 1997 and 1998 S10s as possible donors for a 4.3 engine swap into a Jeep CJ7. I was wondering if anyone knows how you can tell if the engines have the California Emissions option? Any help would be greatly appreciated.
Thanks,
Dan

Beginning with 1996 all vehicles manufactured for sale in the US are OBDII compliant for all 50 states.