The oil problem is from people using them with no O ring. There's supposed to be an O ring that fits into a groove on the shaft. If you search a bit, you can see instructions I wrote about how I convert these to use on 216/235/261 engines. If that groove for some reason isn't there you can use a round file to slowly and carefully make one. Those instructions are on this site. I've used one of these since 1997 and have had zero problems with it. As Jerry mentioned you can use standard GM replacement parts. Maybe I've been lucky but I haven't needed to replace any of mine. I probably need to sell the red one I converted. I also have one of Tom Langdon's mini-HEI distributors but I need to look into it. Something did go wrong there.
