I'm not familiar with your smog and swap rules. Why would anyone find out the motor was a '91? Wouldn't you swap all the emissions stuff from the original motor to the new? Then the wiring and computer and obd-II would be the same as original, wouldn't it?
he was saying his motor is good but the body i junk if he did the motor swao just to change the intake and every thing to the 96 it really seems like a waste of time but that imo. when doing all that work for a stock motor you should just put a v-8 or something and call it a day
I know that the intake manifold is different from the 91 to 96. I don't know the exact year cutoff, but the earlier 4.0s had a cast aluminum intake manifold while my 96 has a plastic composite intake manifold. I don't know if they are swappable or not.