What is accepted tolerance for new aftermarket valve springs?

yellow rose said
nm9 is correct for those springs less than 1% spread on rate is pretty good. As you go up in spring quality you find the spread goes down.

I'm so DAMN glad you put forth the effort to search out the math on spring rates and did your own research and math.

I'd rather lead you to it than tell you how to do it. That way, you learn (not that you are stupid but it seems to me those who do their research do better) and you can pass it on.NICE JOB!!!!!!

I agree 110% with you there. I am also sick of spoon feeding people and with 90% of the population, you tell them something and mostly less than half of the info (if that) will be retained. The best way people will learn is if they make the effort to find out, or discover, for themselves.