Speed density/E-303?

I got to differ with you there. There are many cams that you can use while staying speed density, you just have to be careful in selection as SD relies heavily on vacuum. Crower 15511 is a good SD cam.
 
While there are cams that will work with speed density, why bother, the stock cam is pretty stout.

TMoss on this forum makes something like 280hp to the rear wheels with SD. I think he's got a stock cam advanced four degrees.

PM him, I'm sure hell steer you to a solid setup.