Thanks Aeronaut,

I was hoping to install the fuel tank so it's cap would protrude through the hole in the firewall as per plan. I suppose I could install the tank lower in the fuse and close off the hole a bit. I was just curious if anyone with a similar setup had problems with this, and what their solutions were.

I remember on another thread here, somewhere, someone mentions that a fuel valve would prevent siphoning when the probe was inserted. The prob could be left in after fueling, and removed just before starting. Might be worth a try, if siphoning becomes a problem.