Pulled Studs Not Fun
If your getting the heads done, get the studs pinned at a minimum. Its worth the extra few bucks. I built a mild 350 and did not have the studs pinned. Apparently, number 2 cylinder had an issue with the intake stud and it pulled. Made a hell of a racket and driving it home was miserable. Having to fix what should have been no issue made me a believer that pinned studs or screw in studs are worth it no matter what cam and spring combo you use.