I purchased a 2000 z28 SS yesterday, I got it from an older guy who ended up with the car when his good friend passed away. He says the engine had been swapped out to a 454, to look at it it has the LS1 fuel injection etc... It's has a 454 badge on the fender. The car is fast! (I've had 4 Camaros and 3 t/a's and this one is a monster). What numbers and where do I look to confirm? Thank you.

 

454ci is beyond the max displacement of any stock block, so look for tell tale engine replacement signs. Iff its a 454, its most likely the LSX 454 crate and wont use a common LS1 intake

Post pics. You might have something or it might just be modified stock