They look close in dimensions. the Gasket is the same part number. So the diameter is the same.
The stator has the same bolt pattern, but are slightly different, the 360 having slightly more output and a rectangular connector instead of round.
They look very close. the depth may be an issue, and I am not sure if one is slightly deeper then the other.
Are you looking to put a 260 cover on a 350, or the other way around?