All right guys, I went to the hobby shop to buy the FAI fuel,,, but ended up walking out with head shim material instead. I bought a package of .001, .003, .005 and .008 brass sheet. (the head insert is already brass so I'm not worried about galvanic corrosion).

Ultimately this will be a better solution for me since all I have to carry my planes to the field is an 11 year old honda accord, so two planes, a field box and refreshements (cokes not beers) pretty much fill the car already and having to deal with 2 different gallons of gas could be done but is definetly not what I prefer.

I plan to take measurements of the head tonight, and go to my buddies place to CNC route out a bunch of different shims. I'll start with teh .003, and progress from there, if I don't get anywhere doing this, then I'm only out $3.50 and I'll go get the FAI fuel.

Hope to have some data this weekend.