I know a lot of guys that use comp vs and are very happy with them. I'm a firm believer fo using a vs that matches the cam manufacturers requirements. I have a Poston 107T cam in my engine. It's gone through a set of worn rod bearings and cam bearings. I had to pry the cam from the block. But it speced out okay. so I reinstalled it. From a little research, it appears the cam is a lunati grind, but this is not the cam that is currently being produced for Poston by lunati. Both lunati and Poston recommends a closed pressure of 100psi and I researched the springs used with their cam. A close match was the SBC 1st racing design SHP spring, so I used GM spring listed in my sig. These days I hear that CompCam are the choice for quality and reliability. If I had to change cams, Comp would be my choice and their vs would accompany that cam, as the GM spring would be a little stiff for their cam. So this is the reason for the suggestion to call the cam manufacturer for a recommended spring spec.