I guess I am cheap. I took the stock 68 Bronco distributor apart, cut the housing down with a hacksaw removing everything above the clamp flange. Hit it with a belt sander to make it pretty. Then I tapped the shaft hole for a 3/8-16 screw then install a .500 long screw with some silicone on the threads and a washer. Then I cut the shaft off so it was short enough not to hit the bottom of the screw (plug) in the housing. It has been on the engine 5-6 years and several thousand miles and never leaked or given me a reason to even look at it. It takes up almost zero room and I mounted to coil packs over top of it.
I can;t see why you could not do that with any 351 distributor if it has the correct gear on it.