The B66V arrived in the late 1990s and included an integrated valve. It was similar to the B44V but with a slightly larger head to accomodate elements such as 50kHz, narrow-beam 200kHz, 170kHz and 192kHz.
The retaining clevis pin entered through the valve sleeve. Below the clevis pin is the 2" black plastic screw-down cap retaining the valve sleeve.
The B66V used a low-speed fairing block #33-029 that is no longer available. Other replacement parts are the same as the older-version B744V.