Both my 53 and 63 turn in the mid 11's. the 53 has an 11x8 and the 63 is running a 12x8. The 53 is in its 4th plane! My 91's and 120's run in the 95-9800 range.
You should be propping the little ones to get 10-11.5k. Below that your just wasting your resource.
Good Luck!