Nye County doesn't require SMOG check on any vehicle. Clark County does. In Clark County, any vehicle 1967 or older doesnt require SMOG check. However, accordning to the paperwork I received from DMV, if you perform an engine swap you must meet all emission reuirements from the year of the engine manufacture date.
I spoke with Howell Engine Development
www.howellefi.com and they said they can build a harness with the necessary emissions components built in. I dont believe this can be done with an aftermarket harness that doesn't use and OEM ECM. The engineers at Howell aslo said that California requires two other parameters that Clark County NV didn't mention. One was fuel pump pressure and.. (I forget the other)...
The normal engine swap harness usually has provisions for two 02 sensors. With the emissions requirement, you need two additional o2 sensors after the CATs. It also requires the fuel evaporation canister and the purge valve.
I assume that all these componets are vehicle specific. Sometimes you can cross reference parts from one vehicle to another, but not all sources are reliable. Just because its on the internet doesn't mean its correct.
The information above it based on talking to NV DMV, Howell EFI and checking parts on both
www.rockauto.com and
www.napaonline.com ....