This is what I posted a year or so ago:
https://www.stovebolt.com/ubbthreads/ubbthreads.php/topics/1571332/1Originally I thought the oil was coming up the shaft and so I used a wavy washer and a couple of plain washers to stop it (which it didn't). You need an O ring on the distributor's body (the part which fits in) and that can either be right at the top (since this distributor will not rotate like the original one did) or on the body in a slot. After I added one I never had the problem again. Most of these now have a cutout for the O-ring machined in them. A bit of negative pressure (PCV) helps with this and also other misc oil leaks.
The two I've bought (designed for the 230/250/292/194, etc) have only required minimal work to make them work fine in the Stovebolt engines. 1. you have to shorten the drive tang a bit and reshape the curve as you see I've done, 2. you have to make sure the gear hits the cam gear in the right spot (it should if you follow what I've done), 3. you need to use a relay to protect your ignition switch as there's a good slug of inrush current with these, 4. you have to create a new "collar" to stop them when you install them and 5. you need to make or buy a new distributor hold down thingy (and using this means you could put your O ring under the collar if you wanted because the hold down thing is going to push downward.
Hope this helps. The process isn't very difficult.
