SR20DET Bad Headgasket? Something else?

[KiLLeR2001]

I'm not too sure as to what exactly is going on with my engine, but if I had to take an educated guess I'd say my headgasket is failing. SR20DET redtop, all stock specs with only about 10,000 miles since the rebuild...

I'm getting pressure in my system and oil in my radiator... When I rev the engine with the radiator cap off, the water will shoot out of the radiator. My car however DOES NOT overheat at all. I also am not smoking out the exhaust pipe either. There is a leak out of the front main seal, I'm guessing due to the pressure going everywhere. Car seems to run great up until around 4500 rpm, then the power just tapers off drastically. No idling issues at all either.

When I shut my car off, one of my heater hoses on the intake side of my engine will start to leak water out until all the pressure is relieved. When the car is running however, there is no coolant leak at all. Usually when I go to take off the radiator cap after 5 minutes, theres no pressure left.

I've talked to a few people and they've told me it could be a few things, but has anyone had very similar experiences and can pinpoint the exact problem? I'm going with leaky headgasket but I dread it be something more internal.