gas cap lock function

[lakeview]

Working on a 78 SE picture one showing "survivor" tank mural, (not to my taste), I replaced the gas cap lock cylinder and reassembled same to reinstall. Several attempts ended with the catch positioned wrong so that the key would not turn, as in picture two, right side. Finally I got one together that worked, picture two left side, and on further examination saw that in addition to the difference between Standard and Special caps, the catches are different, picture 3. Is there any shop best practices on putting these together so they work consistently, other than ensuring that one type is never mixed in with another?

 

[lakeview]

OK, so I kept on working on the other 2 caps and have solved my own question!. The long spring tab goes under the actual cap that fits into the fill hole. This allows the spacing for the key to work. Sorry if I cluttered up the site with this.

 

[5twins]

The only tip I can give you for operating the cap lock is to push down on the cap before attempting to turn the key. This relieves the pressure on the latch so it releases easier. In fact, I think "Press Down" is printed right on top of the cap.