Stefan,
Make sure the gap between the 8-bladed reluctor inside the distributor is no more than .025 inches away from the magnetic pickup. Believe it or not, those two stainless hex screws let the pickup move around bit when tightening them up. Don't forget the silicone adhesive to lock it down. And put a little light
oil on all the iron parts to keep them from rusting up so quickly.
You can do it with the dist in the engine, but it's easier with it out. Let us know if that is an issue.
Tom