I had this working once but now its not, cant quite figure out why so I'll try here..
grsecurity-2.1.14-2.6.31.8-200912151745.patch against linux-2.6.31.8
CONFIG_GRKERNSEC_TPE=y
CONFIG_GRKERNSEC_TPE_ALL=y
CONFIG_GRKERNSEC_TPE_INVERT=y
CONFIG_GRKERNSEC_TPE_GID=500
-rwx------ 1 nayr nayr 22 2009-12-17 23:14 test
$ cat test
#!/bin/bash
echo Test
$ ./test
-bash: ./test: /bin/bash: bad interpreter: Permission denied
kernel: [522739.738932] grsec: From 64.101.XX.XX: denied untrusted exec of /home/nayr/test by /bin/bash[bash:25175] uid/euid:10000/10000 gid/egid:10000/10000, parent /bin/bash[bash:25099] uid/euid:10000/10000 gid/egid:10000/1000
id nayr
uid=10000(nayr) gid=10000(nayr) groups=500(exec),1000(admin),80(websvs),10000(nayr)
I am pretty stumped, it should be working.