I don't have any run time experience with the Victor head but I was able to push the Indy EZ head out past 900 hp using fairly conventional parts. Stock valves and valve locations but the heads were ported and then touched up by some of the best in the business. The trick was the Jesel rocker arms which allowed me to run up to 0.880 lift. I used a cam with 0.481 lobe lift and either 1.70 or 1.85 rocker arms depending on what I was trying to do. I'm not sure if the same trick would work on the Victor head but if I was trying to make big power it is probably something I'd try.It does work on these There is a limit to the shaft rocker arm system although the limit is probably higher than where this engine is at the moment. I think the limit is somewhere around 800 hp but I'm sure people have pushed the stock type shaft system past that. Even with the Jesel setup it does take some time to figure out how to get close to 0.900 lift. There are only a handful of springs made that will work and they require specific cups, retainers and locks. I had a whole drawer full of that stuff that I would mix and match. I eventually ended up using a spreadsheet just to keep track of the different combinations. I think I was close to a 2.100 installed height using the stock valves that came in my EZ heads from Indy.