For mild street engines, stock valve springs are more than adequate. But if you've screwed in a big bumpstick for strip-banging or banzai runnin', then pay attention. Our plan was simple: Install a ...

The scenario goes something like this. Our LS3 used to rev freely and make power all the way up through 6,800 rpm, but now it struggles to get to 6,000 and power is definitely down. After a thorough ...