I've put in lots of rope seals. It's not bad when the crank is out and you can properly work the seal into the groove. Doing it while in the truck is not impossible, but it is not exactly easy either.
Also, it's harder to find a good rope seal maker now. They just don't hold up like they used to. or that has been my experience.
I would use the two piece rubber seal and be done with it.
