new cam is comp 12-268-4. gross valve lift is int .479 and ext .48. my heads are max valve lift of .575. min head to piston is .05. so all looks well. now do they assume the rocker is 1:5. as mine are?

also

max valve spring seat pressure 120 lbs. i did not see that spec on CC website BUT someone recently posted this same Q i suspect comp asks for 115 and the prior Q was what is 5 lbs? can i assume in 15 months the springs have worn a bit and are now maybe less than 120 as advertised new?

 

For most engines, Comp list the lift with the stock ratio, for the most part. In a SBC's case, that would be 1.5.

Running 5 more pounds of seat pressure should not have any adverse effects on how your engine operates. However, it should have some positive side affects. Seat pressure is directly related to valve float. Consider what valve float is: when the engine is operating at high speends, the valve returns to the seat with such velocity that it literally bounces off the seat and opens a small bit for a very short period of time. Factory springs only run like 85 lbs of seat pressure, hence the problematic issue of valve float. Now the second you increase seat pressure, you increase the resisting force being applied to the valve when shut. Aka - as you increase seat pressure, you increse the pressure that holds the valve shut, once it shuts. So it is harder for the valve to float.

What springs did you get? But for the most part, i wouldnt loose sleep over it.

 

what ever edelbrock includes in fully assembled performer rpm heads. i was told by the engine builder the heads were very high quality. he mostly sees stock older model vette stuff. vette specialy shop that happens to be a friend. he happens to be my customer as well as i am his. symbiotic friendship/business relationship.