408 Build Thread
I would PM Brian at IMM or call him up and ask about those springs. You really need an expert to answer that question. If you do need to switch springs I would get a full bee hive set up from Brian. The standard 7 degree retainers and locks I think are marginal for that cam and the springs are prob marginal too. I had to upgrade mine to 10 degree retainers and locks and change my springs too.
Your build is shaping up nicely. Just wait till you put the pedal down...