New engine

[PKRWUD]

Odds are, only the short block was replaced, rather than the entire engine. The short block is everything below the heads and the intake. Even if it was a long block (includes the heads), though, neither would cover the injectors, plenum gasket, or MAF. Also, you are going to have a hard time nailing down sombody for leaving the air filter off, and worse, proving that your replacement needs were caused by that. Unfortunately, there isn't much you can do. The parts that you have that need to be replaced or serviced are parts that will require service as they age, and since they are probably original, you don't have a leg to stand on. I really am sorry to say this, and I do feel for you, but I figured you'd want the truth.

Good luck!!

Take care,
-Chris