i went through this...there is no part number for the h block. i was unable to find the h block through toyota parts, i ended up getting a pair from some guy in tenessee and another pair from a guy in south carolina by asking on a couple of facebook groups.

but first i ordered the cross bars with the mounts...no h blocks included. i had to take a bunch of pictures i found on this site and send them to the people i knew at the dealership i bought from and they were stumped. it took me a few times to convince them that the cross bars i ordered were correct, but they were lacking the proper mount (h blocks) for my 2012 TE. the only other option i found was buying an entire new 2014-present rack, which i wasnt going to do.

it took me MONTHS. if you are on FB, ask around some of the 5th gen pages, thats where i found mine. best of luck!