Angier,

The guys that made my exhaust system (early 235) must be the same ones that
made yours - and many others. The initial bend for that cylinder is too
close to the flange to get any kind of wrench on it, let alone a socket. I
ground up a number of perfectly good Sears box and open end wrenches trying
to no avail. My solution, though perhaps not the best though it's been fine
for over 800 hours, was to put small dimples in the flats of the nut and
after running it on as far as possible by hand, using a long punch and
tapping the dimples in the direction to tighten until it was tight.

I worried about it a lot in the beginning and checked it early on every week
or so for almost a year. It never came loose on it's own though I had to
remove the exhaust system twice for crack repairs (another story).

Just another way to skin a cat, though I certainly don't recommend it if it
can be avoided.

Dan Schaefer