This is pretty much how I have mine run. There's a 12:1 purchase under the cockpit floor, and then up through the barney post. It makes adjusting the backstay quick and easy, although to be honest, I don't understand sail trim well enough yet to be playing it much while sitting on the high side.

I'll send you some pics of my setup by email.

J

:: I am going to modify my mainsheet to use a cockpit sole
:: mounted blarney post. I was thinking it would be
:: convenient to route the backstay adjustment under the
:: sole and up through or just aft of the blarney post and
:: use the blarney post to mount a swivel cleat. Has anyone
:: used a method similar to what I have described? If so,
:: would you share some details of your install and a photo
:: or two? I looked at the Harken Duo Cam swivel cleat
:: H216, but it seems like the cleating angle for the
:: backstay might be to low when you are stilling on the
:: edge of the cockpit combing? Any comments, advice
:: warnings?