Any LS swappers in Clark county NV?

[TrkEnvy]

I am wanting to do a 5.3 into my 71 c10 but I wanna know what the laws are for smog. Do I have to run cats because they came on the 5.3 or do they not apply because the truck didnt have cats in 71. I thought that the truck has to only meet air regs for the year it was made, but now im not so sure. Anyone wanna sign a petition to send to our governor to have the date for smog excempt pushed back from 67 to 75 to match cali?? Why are we more strict than somewhere that has 10x the population and vehicles.