I have a cz550 .375H&H I need a load for. I am using 350gr. woodleigh solids and soft points. I have found very little load data for 350gr. bullets. Does anyone have any experience with this sort of load? Any help would be great.

there are several that have been discussed here... do a search for "375 350gr load"

here's one load data

Thornell; I haven't used any 350 grain myself but Hodgdon manual #26 list the following loads for 350 gr.
H4831 72.0 2288 START H4831 76.0 2452 MAX
H4350 68.0 2261 START H4350 72.0 2432 MAX
H414 68.0 2280 START H414 71.0 2461 MAX
H380 63.0 2238 START H380 67.0 2414 MAX

Also, as you are probably aware , do not use IMR powders with Hodgdon data.

Jim