I've got a 350 project that is underway and just about everything is ready for assembly except my crusty looking engine and I've been looking for an engine builder that's familiar with these and does non-stock rebuild work. I came across Giannini's shop through this article -
http://www.bikeexif.com/1972-honda-cb350-cafe-racer - and I rang him up to talk about building a motor for me. He seemed knowledgeable and says he's built several of these for vintage racers and really seemed to know the ins and outs of the motors, the parts and what will work and what not and what to do about it. I left our phone call feeling pretty confident I've found someone that can order the parts I need and do my motor assembly - these are not terribly complicated motors, and if were a stock rebuild I'd do it myself but introducing new parts means inevitable surprises along the way.
Right now our plan is to strip the motor down, bag & tag everything, have my local guy vapor blast the cases/jugs/head and then drive everything up to NJ (I'm in VA) to drop it off with my 'wish list'. Currently thinking +2mm pistons, mild cam, springs, plus refreshing all the seals and head parts. He says he can complete the assembly within a few weeks of dropping off the parts.
Anyone have any experience with him? He seems to have a good reputation around the vintage racing community.