Since the new 2005.0-profile handles 2.6-kernels, also the grsec-sources should follow and move on. There at least should be a masked ebuild availible in portage. Reproducible: Always Steps to Reproduce: 1. 2. 3.
Use gentoo-sources or hardened-sources. I'm pretty sure there won't be grsec-sources-2.6.x. It wasn't a supported kernel anyways.