Correct LA 360 Dipstick???

OK, tech question:

Not sure how I overlooked this over the years, but I was checking my oil and it read WAY overfull. I only ever put 5 quarts and a standard size filter on it. I was due an oil change (once a year) so I changed it, actually checking this time.

I put 4 quarts in it and it's already over full. Granted, I haven't started it, but even after the filter is primed there is no way I am getting a 5th quart in that sump (at least, not according to the dipstick).

1977 360 block, stock oil pan, with a tray welded in. I was thinking maybe my dipstick wasn't the correct one for the pan?? Below are some pics to show what I've got. With only the 4 quarts in, the level is already past the "F" in full.

Note height of dipstick tube:



With 4 quarts it is already past the "F".


Overall dipstick length: