Originally Posted by grizz1

Spot on Flanno

Both Flanno and I run the .4mm shim stack because we have experimented a bit, and have found this set up works best with the fuels etc we use. Performance and reliability is brilliant. There are a few others on here who run the same shim set up as well. It works for us, but may not work for everyone, so experimenting to find the ideal set up for you is the key.
Massive's .1mm set up works for him, but you will also read he has a custom venturi fitted etc. Like Flanno said, you would need to consult with Mark at Massive Mods if you want to vary from what he has listed in the Shimming 101 guide on his site.
My suggestion of the standard .5mm shim stack (plus additional shims if required) to start with, is just a safety thing seeing as you are going to be running 33%. I have no experiance with fuels over 30% so would hate to advise something different and have your motor damaged. PM Massive and have a chat with him about it.
Personally I would drop the 33%, and source some 25% or 30% fuel. That's all you need to get the best out of these motors.