The latest batch of repro '69/'70 hood bumpers are not very good. They are shorter than the originals, and do not look the same as the originals (they look more like the '67/'68 bumpers).
Difficult to install, but not impossible. Use some form of lubricant, and / or shave down the retainer nubbin a little bit so it will pop in easier. I used a screwdriver with duct tape on the end and was able to work the bumper into place.