Really guys? tapping aluminum is not a big deal. I do not recommend using taps from Harbor frieght Tools for something like this. A high quality tap will cut much cleaner threads and make the job easier. You may have to spend 10 bucks per tap but its worth it. The best place to get good taps or high quality machine toos is here:
McMaster-Carr I used to buy all of my hardware, drill bits, taps, and mill bits from them.
My opinion of the self install is that you will gain an intimate understanding of how this system works when installing it yourself and if a leak or issue arises you at least know what your doing to resolve it yourself. At least here you dont have to fabricate anything.
In hobby projects that I typically do I have to design and fabricate my own parts using machine shop tools. From what I see this isnt too bad and to save a few grand on install labor. I am there!! I also want the install DVD video GTM is making.
I do have a question for Modme: How come you didnt install an oil cooler?