i posted this subject to dr alan, from alexhuereptiles.com forums and heres what he said:

rex322 wrote:
my BCI is healthy, but i was wondering something. do they sense heat like BPs? and if so where are their heat pits? thx


That's a great question! Yes they do sense heat, and while the heat pits are smaller and not as dramatically prominent in boas as in some pythons, you will find them on the margins of the upper and lower jaws.