I have a similar starter in my Chevelle. Make sure there are not supposed to be two wires besides the battery cable going to the starter. It sounds like there is an incomplete circuit in the starter wiring. Excuse me if you mentioned it before, but was the motor in the 914 before? If everything worked before, and not now, sounds like wiring mix up or a wire went stray and is hiding from you. I know there isn't a lot of room in a 914 engine compartment with a 2.0L, so a 350 must really bust some knuckles.