From what I see at this point, I'd look into some mild port/bowl work and a good valve job with the existing heads.....maybe even a 2.02" intake valve along with that, plus a thin head gasket to get whatever compression increase you can? Along with that, I'd go right to a cam that will maximize your total combo. With some research, and with so many "shelf" cams available today, I'm sure you can find something superior to what you're running now. Also, there is always a custom grind from one of the good grinders that would fill any void if needed?