Thanks for the info, to bad bisi dous not want to give the specs. I'm thinking of buying a lvl 2 bisi cam for my d15b and i need upgraded springs. I dont mind buying bisi springs but want to know more about the seat pressure etcetera. The lvl 2 cam is not that aggressive like the lvl 3 or lvl X cam, but those cams need the same springs making me wonder if these might be a bit of an overkill. I dont want to cause unecessary strain on my valvetrain.