1: Yes... inverted fits best... BUT you may want to use a Cline regulator (about $60) to help prevent flooding and smoother running
2: yes (left side fo the plane to provide for right thrust)
3: 15x6 seems the prop of choice
4: Stock tank is fine for about 10-12 minute flights (not sure you could put a bigger on in there...
Originally posted by Webjammin
Just tryin to follow this long thread is making me dizzy 
Here's what I've got going on with a UCD3D. I was first going to put a 61FX in it but after asking and reading here on RCU that the 61 will fly it with little power to spare.
I went down to my LHS and picked up a SAITO 100 for some better power, It looks to me that the Saito carb placement won't have a fuel siphon problem.
So now that I have the Saito 100 engine a couple more questions:
1) best if mounted inverted ?
2) should engine thrust angle be set right with a (2) washers under left side of engine mount ?
3) what pitch prop is best for the Saito 100
4) is the stock fuel tank large enough for the engine ?
More questions to follow 
Bob