OK guys, I have been through this part and will say that a stock holly 5160 hp carb will not let you down on the road course. The power valve issue just keeps you from needing larger jets. I have a 383 stroker in my road course car with stock floats and just needed to tune for af ratio. I do have a 750 cfm holley with road race floats and cannot tell any difference with standard floats. I did have to rejet the carb 10 sizes to get the correct a/f ratio
Good luck,
Bain