need to know the spacing of the screws for the stock outside rearview mirror mounting.
center to center
thanks

Dan, there should be 2 threaded receivers on the underside of the door skin top where the mirror mounts. If you're doing the pass side on one not previously mounted, then you take off the interior door panels to see where they are & punch/drill out the top door skin where they are located.

IIRC - Pelican tech section has an article on that, as well as in Paternie's "How to Restore & Modify Your Porsche 914/914-6" book.

If you're just checking the spacing, measure off the stock mirror base plate.

I am aware of the captured nuts on the inside of each door skin...
If I had a door here with me or a stock mirror I would have measured it already.
I am trying to modify some other mirrors and don't have a door or mirror at home to measure.
All of my previous 914s had passenger side mirrors mounted by myself...in the stock location

just measured one....30.00 mm center to center.

thank you very much