I just have the sh*tty .15fe. And because it is not the best engine, that is probably why it increased so much (it could use all of the help it can get!). it probably only increased about 7mph though. But the power increase was incredible also. I do not know if you should do it because you have the SS engine. It does help compression alot, by making a smaller piston chamber. If you choose to do it, you will see an obvious power and speed increase not to mention acceleration.

I also performed #10, which is grinding your headers. It went fine, using a dremel, and I haven't yet got a good chance to try it out.