In the MPC this grommet appears to be "dual named". I see the 378766-S that Jim mentioned, but also C6AZ-6A892-A. It is interesting that the 3787766-S MPC record has a note that says "also refer to basic no. 6A892".
I hate when the same part has two part numbers
The part does NOT have two part numbers, the application has two different parts that will work, assembly line and service.
The 65 MPC lists the 378766-S for 6 cylinder engines, but no listing found for a V8.
Not uncommon. No explanation. Future editions do have the info.
For the 289 HiPo (special) it says "from 5/2/66". Does anyone know why? Were there draft tubes before this?
If that info is from the MPC, it may be for a different hole in the valve cover. Draft tubes were used in 1964 (my 289 HP Fairlane had one), maybe in early 1965. I think that was addressed on another thread.
If someone adds a picture or two of an original that will make this thread more valuable in the future.
There's a drawing in the "Ford Standard and Utility Parts Catalog, 1965" (and 66) page 46 (type 2).
Also if there are known discrepancies between factory practice and the MPC that would be nice to know.
Therein lies the problem. If the MPC agrees with the assembly drawings, you're probably OK. If not, that's part of the function of this forum. Remember - Ford was not building concourse grade cars.
Jim