Okay, I am back- the 428 was a 390 after all. This was clear from the crank and the absence of that weight thingy on the ring gear. I want to replace it with a 428 engine so I will be working on that, but I would have a question about my heads, which are in the shop. They are 390 of course, do they fit a 428? And the intake manifold is c6ae9425-g. I resist boring out the 390 for some reason, but I won't say why because that will irritate Itoldyouso.