no, they are not the same. Same bolt patters, different lenght of input shaft.
I got one W series bellhousing yesterday. Turned out pretty good, but he could only do one because I need to fix a couple of spots on the pattern where it didn't release. I will probably have more cast within the next 2 weeks.
He also told me that I need to let the bellhousing cure for up to 2 weeks before any machining is done to it. That is about what I waited on my 7M bellhousing. So, it will be about 2 weeks before I can ship this one out to anyone.(Give me time to build my alignment plates)