Well long story short. I had my car sitting for like a month or so and the first time that I went to drive it was overheating very badly, so I figured that it was the antifreeze mixture. So I put some 50/50 in with some water wetter and it would still overheat, but not as bad. So then I changed the radiator cap thinking it was releasing some steam. Now for some reason it will only overheat when I drive it for a long time at around 3500 rpms and if I put my heat on it's straight it won't overheat. The only other thing that I could think that it could be is my radiator hose is bad, but it looks straight and doesn't seem to be showing signs of old age. Anyone got any ideas???