For your weight on the 888, start with 50psi in the upper chamber and 100psi in PAR (lower) chamber. You could rise up to 65/120 depending on your likeness
Keep on mind to double the pressure (or close) on PAR versus upper chamber.
Well, i´ve been using 2 ply Maxxis w/ home made no tubes for last years (5?) on my AM and DH bikes. Less than a flat per year, but...
Now i'm trying to lighten my AM ('06 spz Enduro w/ mrz 55ATA), and thought about to use single ply Maxxis with XC tubes and slime, or single ply...
Aircorps are thinner and lighter than 50/50, both very grippy, but Aircorps use to take some play (what is cheap and easy to fix). Of course 50/50 don't have this issue because it uses bearings instead of bushings.
I'm using Aircorps about 6 months and i am very happy. Lot of my friends uses...
We are talking about cranks length for a Sunday, a pure downhill bike. It means: high enough to avoid the rocks and as low as possible to turn fast... both things at the limit, inluding pedals, pins, sag, tires and cranks.
Well... Back to the original question... On a Sunday, as a very low BB downhill race bike, you will not get its full potential with cranks longer than 165mm.
MDJ, DirtyMike, Bulldog and Huck Banzai are not talking about cranks for a Sunday.