I chose to do it all at once because already having everything off for the intake swap made the headers all that much easier.

 

I have done several header installs and a couple intake swaps. IIRC there is absolutely nothing I had to do for one that overlaps with the other, except messing with the EGR tube. That's it.

 

That was probably why. Being macs, they went in from the top pretty easily once all the coil packs and valve covers were off. And it just seemed like I had a lot more room to work once I took off the intake. But that might have had something to do with the AIR and EGR delete.