TDR has a ton of good info but you do have to pay to have full access. Dieseltruckresourse.com isn't as good as TDR but is getting there and they are free.

BTW, my thoughts on Banks is ya might have to rob a couple to buy Gale's stuff.  Serious though, look around because the diesel performance market has blown up way beyond Gale Banks and though he does make a decent product, there are many others out there who make at least as good a product and many times a better product for a whole lot less.