Paul writes: ... I had expected (the EI fuel sensor probes) to screw in completely and seat against the rib fitting.  Is it normal for thread to be sticking out from the rib fitting?

Paul, this fitting is a "standard" tapered pipe thread. It does not "bottom" into a seat or gasket. I'd recommend some fuel proof pipe dope/anti-sieze on the threads; this should do the job.

 

PS: If you haven't leak tested your wing tanks, I'd recommend you do so with all possible fittings, etc installed. BE CAREFUL when doing this, as the tanks won't take much pressure or vacuum (see previous posts to this column). This will give you some assurance about the threads--and other parts leaking.

 

Bob Pastusek