Tube bias for Audio Research Reference 110

I have an Audio Research Reference 110 with 1054 hours. I went to check the bias for the first time yesterday. There is a single control to adjust the bias for each set of two tubes. There is a total of 8 output tubes. The directions indicate to adjust the main tube to 65m and then check the secondary tube to make sure it is between 57 and 73. The slave tube on one set reads slightly high at 76 and another slightly low at 53. The other two are right in the range. Should I adjust the primary tube lower or higher than 65 to get the slave tubes in range?
It sounds like a perfect question for Leonard at the ARC factory. Give him a call...he is always right on and willing to help. Good Luck!