Ok. You might need to go bigger on the secondary side too but for now leave the 31 in it. Get the primary's working correctly first then tune the secondary's. There is a lot to consider when choosing a cam. Took me a while to learn all the aspects and I'm sure there's still a good amount I don't know. I usually call up a good cam grinder (Bullet cams, Racer Brown, Lunati, Comp cams, etc) and talk it over with them and have my cams custom ground to the application. I know what generally works but their the experts and can recommend what's best.