I bought some valve springs today for my new cc306 and the guy said id have to mill the head for them to fit. This sucks because I dont want to remove the heads. Ive seen other valve springs that said they fit without machining. True or False. Also has anyone put these springs on Lt1 heads without machining? They dont look any bigger then my Lt4 springs, just beefier.

Thanks,
Nick

 

The Crane 10308 valve springs are good to .600" lift and don't require any machining of the head.

Another good spring is the K-Motion K-800, which also don't require any machining. These springs are good to .700" lift.