I installed the VANs option while building my -4. The kit is complete with all mounts and instructions. The flap control weldment is different than the one used in manual flap set-up, but the original could be modified to eliminate the flap handle attach point and install the drive arm for the flap motor jackscrew. There is also a second set of nylon pivot blocks with the electric set-up. All components are under the tunnel floor. Jim's set-up works just as good, and I have seen several set-ups in the side panel, which may be an easier retrofit. Either way, some re-work has to be done, but nothing major. here are a couple pics I have of mine from the build days.