When I had my Brittain autopilot installed, the folks there said it was set up to work with a gps. However, your best bet is to call Brittain and ask them directly.

Thanks, I checked with them and it looks like it will work. I will post some pics when the upgrade start.

I have the Brittain with a GTN 650 and standard 106A and it works great!    I can intercept a track on the 650 utilizing the heading bug.  Works great!

I also have a Brittain and it works with my Trimble.  Since my GPS is old, it could not do coupled approaches but a GTN solves that issue.  An interface I believe is required (like http://icarusavionics.com).

I have had my 67E model for only a few months. When purchased My goal was to get the Pcs and auto pilot working. Brittain industries is a great help. Testing the vacuum lines revealed a bad rudder servo. Less that a couple hundred invested to rebuild, and the entire system works great. Linked to a King 155 and a gns 430. So far cap, track work fine. The signal 'voltage' is from the 106A not the radio so the 2b box doesn't care what the nav source is. It's needle deflection that matters. I'm still working the flow of operation in flight. So far very helpful in IFR. It's hard to believe such an elegant system was installed in 1967!