2jz headers on the 7mgte
 

Im guessing it would be possiable if it can be done you'd have to weld the holes up and then redrill new ones, poeple make custom headers all the time would this work?

The pipes won't match up. The 2JZ pipes are closer together. I put a lexus 2J manifold up to the 7M, both NA's and the 7M is longer. You could possibly remove the flange and and collectors and try and make them line up with a 7M flange. Would have to be made custom of course.
The lexus collectors from the GS300 I saw had an oxy bung on each 3 pipe section.