9375-2
I thought HP is the new style casting verus the original style dominator in which case they look quite different. The HP series are all that have been made for several years and anything sold new by Jegs will be HP. Correct me if I am wrong.
I have used the 9375 with the annular boosters on single carb BBC applications with just air bleed changes. They do tend to go a little rich on top end though in 1/4 mile.
The Ultra series is just billet metering blocks added and some updates.