81 Regal Doesn't Pass Emissions

Ok here it is, I'm in the middle of buying a 81 Regal off of one of my dads friends. Right now its running a rebuilt 280 V-8, the previous owner before him swapped that in place of the original engine. The V-8 runs very smooth and fine but I think when they did the swap they might have left out emissions equipment. Might that be a reason why its not passing? Any suggestions on what I can do to get it to pass are appreciated. Thanks in advance for the help.

did it finally pass?

If it didn't I had a 80 regal that didn't pass, and iI made an adjustment for the throttle plate and it passed. I acually made it close some and the hydracarbons went down.