Cool build, dude! Can't really tell how that rear dump exhaust manifold clearance look? Having put a 5.3 in an 80 with an electric fan, I had lots of problems with it. Ended up putting a clutch fan in it, and it cooled a hell of a lot better.
Having done a few of these, it just really depends on what you are really after. If you're a purist, be pure. If not, go for what you want. Just to provide you a left turn on what you're trying to do, my next project will be an FJ60 on an FZJ80...