? about 39 box adapter to model A

Who makes the adapter to put a 39 box behind an A or B engine? I have a new project that might require one. Thanks in advance
Harell

 

AC&R:

http://www.partsformodelafords.com/store/category.cfm?Category=27&CFID=860874&CFTOKEN=4637786&StartRow=16
There are other sources, I don't know if parts are the same. You can do it all with B parts, too, putting the late gears in a B case.
Many of the parts in the kits involve bracketry for radius rods and pedals, since the stock A bellhousing is a major structural piece.