A guy in out club has a Buker Jungman (sorry about the spelling) with a Saito 150 and an APC 16x8. Beautiful plane. Flies real good. I had a Saito 180 that i was getting about 9800 with that same prop. I switched to a Zinger Pro 18x6. Awesome combo. I would say as long as you are getting about 9000 give or take 100 with a 16x8, then a 18x6 would be good also.