Too many things to look for to list in this post.
Start with Lycoming Service Instruction
SI1435. It is available on the Lycoming Web Site. I have it linked above directly to the Lycoming web site.
Remember you need the accessory case machined to accept a governor drive adapter. The crankcase needs to have the correct bearing in the nose and a port on the right hand side of the engine in front of cylinder # 1.
Hope this gets you started down the road on what is needed.