i have also read that just the EGR bump won't do a whole lot. The exhaust ports in E7's are pathetic - they only flow about 120 cfm. In order to increase that number, you'll need to open up the exhaust port to a larger size. If you have a set of headers, you can make a template out of paper that matches the size, shape, and location of the port. Then, scribe on the head, and go to town. Most shorty type headers won't have an opening that's big enough to get you into trouble (i.e. grind into water passage). You'll neveer get there if you use a dremel, and the air die grinders will have your compressor runnign full time. The only way to do it is to buy an electric die grinder (they run from about 100 to 250), and some good carbide bits (about $60 for a set). It may not be the best bang for the buck considering that you'll probably need to buy the tools, and then you'll still spend a few hundred getting the heads rebuilt but its still cheaper than new heads, and its something that you can say you did yourself. If your running a stock intake, no need to mess w/ the intake side of the heads - it already flows as well as the intake.
most horsepower/dollar = new heads