Cam only gains?
First do bolt ons and stall. When picking your stall think of the cam going in (extention points), do suspension mods, race that thing.
Once you have it down, add a cam, and you don't need the biggest, but you need the "RIGHT" cam.
Without all of these supporting mods, you just have a big dog on your hands.
my 2c
The trick to optimizing those cams is a balanced combo which requires a boatload of supporting mods. Otherwise you have a motor that sounds like a dragster but moves like a turtle.
I'm A4 and I drag regularly (just in case you think I'm talking out my *ss)

