I would say do it and post the results here for the next guy to know what to expect I already stated my experience with my 318, but I knew I wasn't keeping that engine I had a 340 on the stand so I didn't do much just the duals, cam, 600 Holley and 3.91s RPM wise I hit the ceiling pretty quick meaning I could tell when the engine stopped pulling. Looking back I wish I would have kept the stock 318 cam and ran that before throwing in the Summit piece just to see what the difference may be between the two. I can say the torque was there but not the top end so much I would admit the 3.91s may have been too low a gear.