I purchased a set of crane golds (10-1.6). On them is stamped what the rocker ratio is and another number below that. When installing them, my buddy noticed that on 4 out of the 16 roller rocker they have the numbers + -12 instead of +- 05. What does that number mean? Are they all the same or do i need to get four different ones. Im not sure if it is just the tolerences or if it is completely different. We are now on day 5 of the mighty cam install and this is one of the last things we have to put on.