Running a liquid cooling system will help control the 350s inherent overheating issues. I run a CX500 cycle radiator without a pump on one of my 350s for several years and have not had a seizure since. My buddy ran the same set-up but has one stuck piston, but we think that his wide open jetting was off.
I also run a pump on my 420cc/350 connected to a switch so I can turn it on after warm-up and let it keep pumping for a good cool down after riding. The pumps are made by Bosch for heaters on European sedans like BMW, Mercedes, Audi, etc.
I add a cheap automotive dial gauge to monitor water temps at all times.
More questions or want more pics, just ask.
Gary