This isn't hard to figure out, surely you've kept a log or something of your fillups if you're actually getting in the 20s because that is unheard of...hence my skepticism
and driving a 40 mile round trip while being intentionally easy on the gas pedal and returning to fill up isn't exactly an...
still waiting on proof from OP. spoiler, it won't happen because he's not getting 20s mpg
this is as bad as the cummins guys claiming 20mpg while towing
If you have a really good trans jack that can support the trans/tcase all at once, do that.
Otherwise remove tcase first. Then Remove trans and drop down and completely out of the way. Not enough room to just move it back to change the clutch
I'm not familiar with the location of the fitting on the 454s but it was really easy on the 350. Just tap that lisle tool posted above into the broken off fitting and it will turn right out.
I replaced mine with a 5/8" (??) hose barb to never have the issue again