Hp/torque Increase?

We all know the Dyno is the only way to tell for sure, but I would appreciate your educated guesses concerning my chevelle. How much of an increase in hp and/or torque would the following modifications to my 307 chevelle make. 1) 2bbl-4bbl(holley 600) 2)Single to dual exhaust(stock manifolds) 3) Raising the compression by 1 full point(ie 8.5 to 1 to 9.5 to 1) Just throwing around some thoughts.Thanks everyone.