Smog problem...wrong engine? 454 chevy silverado 2500 1989?

first off a 454 can only be a 7.4 liter, the 8.1 is a Cadillac 501. since the crate block is after market, it can have elevated compression and little to no smog equipment. i think that your best option would be to find the local referees office and take it in there and talk to them about the situation. i had to do that a while back for my car because it did not have an egr valve but that was from the factory like that.