Do you know if they have any results with the standard 171 version of the ProMaxx? It's not far behind the Shocker for peak flow, about 30 cfm. I've got a set and I'm trying to decide if I send them out for the Shocker treatment or just use as-is.
I witnessed the shockers on the bench getting flowed up to 500 lift and they flowed very close to advertised...so I would assume that the standard Promaxx heads flow as advertised...currently the shop has no small block Promaxx heads in stock...