I had no problem getting mine in position after removing the dipstick and starter, but then I have a 12,000 lb Rotary lift which gets rid of some of the ground clearance issues presented using jack and stands.

 

I took off the oil dipstick, alternator, starter,and the valve cover and I got the header in from the top. I did not have to loosen the motor mounts and jack up the motor either.

 

Are you installing the emission's legal headers with the AIR and EGR on it? If so, you have to come in from the bottom and most likely unbolt the motor mount to slide it out of the way. It doesn't matter how high the car is off the ground, the EGR and AIR tube will cause problems. There are 3 bolts holding the motor mount to the k-member and 3 more holding it to the engine. I removed all 6 since I was replacing the motor mount anyway but you can slide it out of the way if you remove all 6 bolts and jack the engine up while your at it. If you're installing non emission's headers then it's probably just a matter of jacking the car up high enough.