Hi everyone. I have a 69 gts with a 340 in it. It has rpm breakup at 4500 rpm where it feels like it’s hitting a rev limiter. I was looking at some things today and pulled a valve cover to take a look at the springs. Is it normal to be able to spin valve springs by hand with a rag ? The compressed springs I can’t spin but the non compressed springs spin fairly easy. I’m not seeing anything broken. Thanks.