If you want to review my Gramma car thread from the last couple years you can follow the swap we did from the original 160 hp Pontiac 350 to the 400 hp 455. It was easy - just bolted right into place with the same parts. There are even certain cylinder head combinations that give you a really nice 9.5 to 1 compression ratio. Our 1975 350 just happened to have that exact pair of heads on it to begin with so it ended up just being a short block swap with a 1971 455 block I found locally. I even did a shaker hood swap last month with factory parts.
https://www.yenko.net/forum/showthrea...=113621&page=7