Thank you for the discussion. I have a 1050 dominator as well as a 1050 standard Holley carb, so I will run the same size carb with either manifold. The Trick Flow 270 heads flow 352 cfm @ .700 lift. An article written by Steve Dultich several years ago tested the air flow of the INDY dual plane manifold and found that it flowed an average of 300 cfm as cast and 360 cfm after Helgison opened it up to max wedge size. This would almost match an unported single plane intake flow wise. I agree that I would be giving up some horsepower with the dual plane. Just not sure how much. My cam will be a custom grind from comp cams. I will not turn my engine more than 6100 - 6300 rpm. Based on Flyfish's comments I will purchase a higher stall converter. With the torque the engine should be making, I probably will not use one over 4500 rpm though. I did find an article where INDY did build a 543 very similar to what I am building. They used their dual plane manifold and a too small hydraulic cam with SR heads and made 613 hp and 700 torque. However I learned a long time ago not to believe everything I read. I appreciate everyone's opinion.