Small Block Intake

I ran those springs (sold as a kit with their retainers) on new EQ heads w/stock length magnum valves in my 410 stroker. Cam was a 280 advertised, [email protected]” with a calculated .517” lift (w/1.6 rocker ratio but actual lift due to geometry was less, I never measured it though) Those springs should be good for about a measured .540” lift. You could definitely go with a bigger optimized cam: with more duration @.050” etc, and maybe on a better LSA? and depending on geometry losses even bigger “lobe” lift.