I have a 1958 Cadillac Coupe Deville, in about a million pieces. The guy I bought it from sold it to me because his teenaged son started “working” on it and took it all apart and just left it there to rust. I had to make three trips to get all the pieces, but it is at my house. I had dreams of trying to get it as original as possible, but the more I look at it the more I am realizing I should make a nice custom out of it. I want to start with the engine, the front fenders, hood, grille and bumper are off, so I figure that this will be a good place to get going. The original engine is not running and is in pretty bad shape. I think it would be best to pull the stock V8 out, save it and find a 1970’s Cadillac 472 or 500. My questions are: is this a good idea, can I use the old tranny or should I change that too, what would be the best engine (and tranny) to use?