Surprising #2 & #3 body bushing differences-Anyone else note this?

[68camaroz28]

We are restoring our 68 Z/28 and just yesterday I was checking out the ol' NOS body mounts I have. Some were purchased in the late 70's early 80's, and others maybe mid 80's to early 90's. I posted this information on the restoration thread going on in camaro.net but thought it would be worthwhile to communicate here additionally as I'm sure many have noted this but probably many like myself had no clue.  First example up is #3901361 position 3 under the seat. The picture shows two NOS same part number cushions but note the differences. The one on the right is the oldest of the two. Is this old news or Learn everyday

And a close up of the older version. Assumed it was a supplier change or some significant change as the years went by but same part #.

Now part 2 of changes! I could be totally incorrect but thought bushing #3928380 (under firewall) was later superseded with 14008366 but look at the differences between these two. Some significant differences......

[68camaroz28]

Guess everyone else knew or?
Happy New Year......

[big iron]

I wonder if after they are installed, is there  a difference in the installed height?
Your post brings out the fact that service replacement NOS parts are not always the same as factory original and should be checked against an original.
Bob