NOTE:
On older 66, 67 and 68 reels a 36-60CH may be required. It measures .248 (roughly 1/4 inch) from just under the cap to the edge of the dropdown.
The 36-209 measures .283 (roughly 1/16 inch longer) Penn may have changed the 27-66 plate at some point, although there are no notes to that effect.
OPTIONAL
Any reel that uses the 36-209 can use:
(Applies to: 60, 60-LH, 65, 66-67-68 (Measure!), 125, 505HS, 506HS, 970, 980, 990 )
36N-209 and a 69B-600 removable c clip
This newer style is held by the clip instead of being peened in place.