Driveshaft front rubber bushing?

[velozi]

I am about to take out the 2 piece driveshaft on a 76 and see in the gide a reference to a rubber bushing inside the front part that holds the flex joint.

Can not find any vendor that sells or mentions this part. Is this a part that needs replacement now that I am changing all u-joints, flex, bearing and suppot? If so, where can I find it?

[So Cal Mark]

it's a seal and no longer available. No reason to remove the front hub if you're changing the coupler though