Ken o conner may build some nice blasters and 250rs, but he dont know
Chit about zillas. I called him about a motor he built in a 500 i was looking at buying
a few years ago.  He had an attitude about questions regarding
O rings and squish for the head, flywheel welding, reinforcing cylinder ears,
and he said he didnt use billet thrust washers.
That 5 min conversation told me i would not be buying that particular quad
and that Ken isnt very knowledgable about zillas.  Ask some hard questions
before you let someone cut up your motor.