Any knowledge on a UN1-12?

[Ryan]

Hi all, a UN1-12 came spare with my GT40. I am looking to convert to SBF soon, and plan to use the Tornado bellhousing conversion on this box to build up and transfer in.

Problem being I can't find what a UN1-12 is, or ratios etc. Have tried google and search here, but if there is something, I am missing it..

Thanks in advance.