Definitely. Rent a valve spring compressor from Autozone for free, if you don't have one. Plastic blast media shouldn't hurt anything, but it's better to be safe than sorry. Make sure you put back the valves in their respective places...don't mix anything up! Take a small box (like an old shoebox), and put the whole valve assembly (valve, spring, retainer, locks) front to back, and passenger and driver's side. Tell the blaster to NOT direct the media at the valve holes, or better yet, duct tape over the holes, or use rubber corks. They will be pretty when they're done! My intake looked literally brand new.