Prop height for 201XL w/ Yamaha 300

Any suggestions for a good starting point for prop height for this set-up. I've been lucky enough to get the boat out a few times in this awesome weather in MI and the boat starts to chine walk at 70. I've been reading a lot on chine walking and will be trying to get as much seat time as I can but I'd like to make sure I'm rigged optimally as well. I definietly need more experience. Thanks!

I say start at 3.75" under.....but what do I know?