Overheating Issues!

So I'm having problems with my satellite running hotter than it should be lately. It does it both in hot weather and cold weather, so it isn't just because of the california heat here lately. I replaced the thermostat, thermo housing, both radiator hoses, and bypass hose. I CANT figure out why its running hotter than normal though. It wont go past the Hot mark, but its definitely hotter than it should be. And I notice it runs different when its "overheating" like that. I've had the car for a while now and have only been having this issue for past month or two.

Any ideas of what it could be?

Somebody told me it could be that my timing is retarded and just causing my engine to run hotter..could this be possible?

Its a stock 360 from an RV