You know, I've seen Jim's direct port engine bay/setup picture many, many times, but I've never noticed how damn close the bends are to the rad support/cover!
I wonder if he had problems with the lines hitting the metal there! Our engines have some considerable movement when revving, etc.
I would be careful about how much room you allow around your lines. I know someone had troubles closing the hood, because he kept them too high up the runners.
I can imagine tapping the runners to receive the nozzles would be a touchy job as well! Personally I would have a machine shop tap the lines in for me to be sure it is well done. But then again I don't have an abundance of machining/tapping experience.