What i mean is that the cams will literally chew your rocker arms. They will score and make grooves in them till they just don't work as well as they should anymore. As for the todas I know Dan over at godspeed will sell the todas with portflow springs. I personally haven't used the combo, but he's sold that combo for a pretty long time and so I assume that it works well enough. Otherwise he would have pulled it a long time ago.