Street Performance engines generally make 1.5 to 1.9 hp per cfm, 175 cfm head that's 263 to 333 hp, for a 200 cfm head that's 300-380 hp, going up 25 cfm should gain 30-50 hp, a drop of 1 cr point should be around 10 hp loss, so a 20-40 hp gain. Obviously this ain't meant to be exact.
