Hi all could someone help me out I have a 455 being bored.030 over at a machine shop I have a set of c heads that came with the motor. I plan on using a comp cam 274h and the heads have been worked on may have been milled my machinist asked to see them its had a valve job and had hardend valve seats installed . can someone tell me what the normel valve spring height is for a set of c heads or what they should be using this cam. Also can I use stock rockers with this cam or do I need to go with roller rockers ? Thanks for ur time.

 

Uhhh, where do I start.
Cam has nothing to do with spring height, nor does milling the head surface.
Early C heads are around 1.680, later ones are around 1.800. Your machine shop can check this for themselves if they have the valves, retainers and locks. If they can't, then you need to find another machine shop.

 

ok thanks