Cheese grater? LOL
Me and Taylor were talking to Jeff and Alex of the Illinois GP Club and they havn't removed the MAF screen (I'm assuming thats the cheese grater). I have no plans to remove mine either because no one has dyno'ed this and the benefits are only word of mouth.
As for the differences, they were subtle over the years. The TB grew in size and I believe the cam was altered. I dunno much about that, but I do know you can make a L27 fast.
Like you said, the basics are 180 stat, cooler copper plugs, wires, exhaust, etc etc.
The intake can be any cone system for the most part, just build your own CAI box if needs be. For an exhaust don't go any larger than 2.5" on an L27. After you get through these "basics" you either have to tune to your hearts desire to get every ounce of power out of the engine or take the quick route like I did with my old car...nitrous.
If your seriously interested, take the time to research your options. We don't want another dead Bonnie here.