Installing a 99/00 motor in an NA

After consulting with my old friend Search I have a few questions.

1. Is any info that you guys have found on swapping an early NB engine into an NA?

2. Is the NB block (without crank, pistons, rods, etc.) the same as the 1.8L NA block?

3. Will an NA header fit an NB engine fitted into an NA?

I believe the blocks are the same. Any 1.8 header will bolt up, but here is the catch. They have to have the same year exhaust from the header back. In other words, the heads and exhaust ports are the same. Where there were changes are under the car.