Mel, that sounds like a great engine. Matter of fact, very close to what I used to build my 6.9 for hauling duty. I've sunk of few more $$$ into other things for mine, but that's a dang solid platform for a reliable hauling IDI engine.
One thing I'd add to the "good idea" pile.... Changing all your 6.9 crate engines to the newer 7.3 rocker arms. Make sure to check and see if decking was needed on the block and/or milling of the heads. Either may warrant reduced compression height pistons with that change in cam timing. Other things on the heads that are worth considering... valve guides and inconel or stellite faced exhaust valves.
Heath