Speed Tech torque arm question

[rugbyguy]

Hi Guys,
I am in the process of buying a speed tech torque arm system for my 69 Camaro from a guy who has changed directions on his project. The stumbling block for me right now is that his kit is set up to use a Ford 9" and I have a 12 bolt. Does anyone know what the differences will be between the 2 systems? I would prefer to keep my existing 12 bolt as it is original and I have put some $ into it. I have tried emailing speed tech directly and haven't rec'd a reply yet so this forum is my next step. I don't want to wait to long and have the system sold out from under me .
Thanks in advance.
Jeff