Who would be interested in buying a 5.7 Hemi A Body car?

I actually was asking, if you put a new motor, I.E, a 5.7 Hemi in a slant six car, doesnt the slant six car now have to go through emmisions now, because it has a modern motor?

I think here is Wa. the rules are the car can have what ever options were available for that yr car, but if you install a modern engine it has to have all the emmision controls on it.