That part looks good. Hughes says my Victor heads with standard valves only allow 660-680 lift max. I don't know for sure. I believe my current springs are 1.550 flat tappet springs and hoping to reuse the spring cups, titanium retainer with locks on the new Pac springs. I see CNC motorsports has the 98543(1243) pacaloy springs for $280. UDHarold cam has been ordered, so i'm on my way to roller after the T ram test run in the spring.
You can get more installed height using +.050 retainers and locks. My 511 is over .700 net lift with standard length valves in my Victors. Hughes told me the same thing as you when I was figuring out the IH and camshaft. The problem I ran into was getting the roller tip centered on the valve at that lift. I used a b3 kit to correct it. Engine made peak hp around 7000-7100.
