For what it's worth, I purchased a circle track roller setup for my two liter a couple years ago from Esslinger.
As my engine was being assembled, the guys at the machine shop told me that Esslinger gets their cams from Crower.
They had to send mine back and have it reworked. The reason I was told was that the application wasn't made for street use and that I would be changing cam bearings more often than I would wish. This package came with straps that are welded to the top of the towers.
The folks at Esslinger told me then that they were not going to stock much for two liters anymore. If one were to contact Crower, they may still have some billets that could be used.
Al