Hmmn, never thought to mention this, but since the original poster was considering a crate engine, maybe a 502 would be a better comparison?
Reagardless, there's really not much to do to stock SBC towers to make a BBC fit, been a few years since I put the 454 in my 57, but seem to recall I moved my mounts forward about a 1/2 inch. But not haveing done this in a newer truck, I'm unsure.
As far as accessory brackets, since he's considering a crate engine and won't be limited to the "old style" of V Belts, he can go modern (and better) with Serpentine setup, which should be plentiful from late 80's on up to late 90's.
I guess it depends on what you want to do with an engine in said vehicle.
I like going fast and quick when I think Big Inch gas engines, and since I'm partial to the General, it'll always be a BBC. If dollar for dollar you can build a Big Inch Caddy engine that will outrun a BBC engine, you have a very well kept secret
