I've look through the forum and couldn't find anything on it but is it possible to replace an 8 valve head with 12? You know without modifying any water jackets or anything

Hello everyone, this is my first post. Don't see why thats relevant just wanted to throw it out there. Anyway I've been on this website for a while now and seen alot of amazing 3.0 and it has inspired me to start my turbo duster project :) I just had one question i couldn't answer myself. Is it...