Looking at the t&d site, there is a different part number for the -1 and B1 heads, however the offsets for both are shown as the same. It could be that the only difference between them, as sold by t&d is that the B1 rocker set comes with the stands.
And, t&d does show a part number for a "1.52" ratio set for B1 heads.

I'd say a call to t&d would clear things up.