Well I guess the only way you are gonna get there is a lot of tuning, and that isn't gonna make up about 40rwhp. You are pretty much maxed out on your setup with out Tearing into the motor. Otherwise, cobra motors (or explorer motors)would be 300 RWHP motors from the factory.
The longtubes might give you a max of 10rwhp (doubtfull)
The synthtic fluids might net you a max of 5hp
You might get a 5hp gain from the electric fan
You already have an aluminum d/s and the fan is on the way. You already have all the other boltons that are required to get there. A cam swap might be the best et for the combo, but that would involve tearing into the motor. You have a great setup. The quest for power and speed will always be there, but if it runs good, driveabilty is good, and if emissions are ok, then be happy with what you have. Those are very respectable numbers for what you have. Think about it, you basically have an explorer motor with a cam that runs (assuming) pretty well. Good luck in your quet for power.