I wanted to share some findings regarding 65-66 u-joints:
First, some pictures attached. The left column are the only non-greasable ILR i've been able to find, front (top) and rear (bottom). The center column are original plugged joints. The right are later BW service joints that match Ford service joints I've seen.
Going through more ILR driveshafts, I've found several MBW (Mechanics Borg Warner) u-joints with plugs, as well as rear joints with strapped caps.
The '65 and '66 Comet/Falcon/Fairlane/Mustang shop manuals say "The universal joints are provided with a threaded plug which can be removed for lubrication when necessary." That sentence is conspicuously absent in the 67 and later shop manuals.
I found examples of the #C3AA-4868-G slip yoke for both ILR and OLR applications. Any thoughts as to why a BW-supplied driveshaft assy would have a Ford/Dana slip-yoke?
A Feb 65 San Jose C-code I looked at has inside lock rings.
A March 65 San Jose K-code I looked at has outside lock rings.
I'm just stating this, i'm not claiming anything about the OLR/ILR transition, or K-codes being all OLR.