I'v got a couple worn [noisy] rockers on my 307 rather then replace them i thought why not replace them all . Summit sells their own brand of long slot 1.5 ratio stamped rockers for around 50.00 cam is a Crane 266 energizer with .440 lift anybody use these before and i wonder who makes them for Summit [Crane , Manley]Also i have read that stock GM are not well designed and are probaly closer to 1.4 ratio ,I figured this may give some more lift and performance , what do you think