Ok... Here's what I did:
1. Disconnect the battery.
2. Jack up the driver's side of the car, place a jack stand underneath the driver's side front.
3. Unbolt the motor mounts (both sides).
4. Place a block of wood on your floor jack, position the jack underneath the oil pan.
5. The passenger's side header should drop in without much of a problem. You might have to jack the motor up a bit to get it in, though.
6. Jack up the engine as far as it will go. You can remove the distributor cap to give you some added clearance. BE CAREFUL, the distributor will be pressing against the firewall at this point.
7. Take a break, have a beer.
8. Disconnect the steering linkage under the driver's side of the car.
9. Have a buddy stand on the driver's side of the engine with a crow bar. Position the crow bar between the motor mount and the engine block.
10. As your buddy pushes the engine as far as he can towards the passenger side of the car, drop in the driver's side header.
11. Lower the engine down off the jack.
12. Take a break, have a beer. Offer your friend a beer.
13. Bolt the headers up to the engine.
14. Put the steering linkage back together.
15. Have the front end aligned.
I think that's it... Like I said, it was a pain in the butt. Next time I'm going with headers that don't wrap around the steering linkage.