Like 340's, I always thought they ran hotter and extended periods of higher rpm cruising or pursuit. higher temps translate to more expansion. Also the hard chrome gives a harder surface, so less wear. You did get me thinking about the intake valves also. 1.88 diameter 340 and HP 360 intake valves were different from the standard 1.88 intake valves, 4 lock grooves as opposed to two lock grooves. Pretty sure they had hard chromed stems, but not sure if the stems were undersized. I could go down and measure some in my stash. As for the cam I'll look up the number. I have an NOS cam also.
