Hope this isn't too random a question Steve (and others!)
This is the DME in my car, and my mech suspects that it's been chipped (the tester won't talk to it when he tried to do an idle adaptation). Part number is 911.618.124.03.
But I happen to have a spare, with a slightly different part number: 911.618,124.04, and it doesn't look like it's ever been tampered with.
Would these two bad boys be interchangeable on a plastic-manifold 964?