why am I over heating driving over 40 mph

After wasting your money on all those things, you have one more task to do: Replace the catalytic converters. It's the backflow resistance that's overworking the engine.

Sounds like a bad water pump. An engine that overheats only while driving it's a coolant circulation problem. Other causes can be clogged cooling system passages, air trapped in the cooling system, a stuck closed thermostat, or a slipping/misrouted serpentine belt. Hope that helps! Jim