My uncle has it on his '65 fastback's 306. It produced 320 rear wheel horsepower with an Edelbrock RPM and Edelbrock 750 cfm carb. I'd say that it's a pretty good package. Just make sure you have some beefy tires or you'll go up in smoke at the track. For what it's worth, his package made more horsepower than my 306 which is equipped with AFR 185's and twin Edelbrock 500's. However, my quarter mile times are in the 12's compared to his 13's because of the tires.