You'll easily make 300 horse.... Might want to take a look at the entire Edelbrock Performer RPM package for the 390's. The heads, cam, intake, and carb are offered as a package and designed by the engineers to compliment each other. I'm a Ford guy, installed a number of these Edelbrock packages on customer cars, everything from a 302's to a 514... Never have had any complaints about their performance......