So about to start on my GC Auto to Manual swap. When i was researching this i had a lot of questions so i will post as much as i can on the subject and try to make it good with pics. This swap will be a 2003 WRX wagon complete drivetrain into a 2000 GC6. Wish me luck!

 

Completed so far:
Peddle swap. Swapped the GDA 3 peddles and had minimal issues. The top bolts for the peddles did not line up with the GC dash. Recommend drill aprox 1/2 inch down from the original mounting points on the peddle assembly to ensure proper mounting. At first it seamed the assembly did not want to go however with a little play and some elbow grease, it went in and looks great. Master and slave are easy as well because mine had a rubber plug where the master rod sticks threw the firewall. If you are doing a GC to GD dash, you should not run into this because the peddle assembly should line up good. Photo soon.

 

Nice! This should be an interesting build.

 

Previously, the gas peddle went in perfectly. direct swap. It was the second set that had a slight alignment issue on the top bolts only.
In the second photo, this is where the clutch master will sit. no need to drill since Subaru just placed a rubber plug in the master's spot.

 

Delayed because of repairs to body and awaiting for some seals to come in.

 

Good luck with your build . I'm currently gathering a few remaining things to start my awd and built 2.0 wrx swap 20g