Small block valve springs upgrade

The 942 looks like it would work to. That one never came up in my search. And the comp cam rep never brought it up either. Even when I asked about a single spring. I am very thankful for this site and all the great information. I already have the retainers, and I have the part numbers for the locks. If summit will exchange the springs that will be the route to take. They say there instock. The only question is if I need over 300# pressure at open. I have a 296 duration with 246 at 50 on the exhaust and .510 lift. ?