The vortec 454 was made from 1996 thru 2000. It replaced the throttle body 454. that was used from 1987 thru 1995.

I would question the condition of the engine if he only wants $ 1200 for it, sounds like a builder to me. I bought a rebuilt the other day and the core charge was $ 900.

I am working on a 496 to replace my 454 with, using the 454 top end it should be a fairly easy swap over.