I drove the D25 today for the first time with the new engine. It runs good, but three of the five freeze plugs are leaking. I installed several of these (1-5/8" concave discs) while the engine was on the stand. I removed a few and re-installed them just to check
how tight they were. I tested various dimples from small to large, deeper, wider etc. Ultimately, I installed all of them with the dimple size that seemed tightest, but I never had confidence in them, because they seemed too easy to pull out. I should have known better than to use them.
Moving on, I doubt I will be able to install another set with the engine in the car any better than I did on the stand, so I'm looking for an alternative. I read previous threads on the topic and there were a couple of mentions of Dorman 568-010 (metal with a spreader bolt). For lack of an alternative, I'm thinking of replacing all five with these. I used the rubber expansion plugs on a few projects years ago (SBC) and never had a problem with them. Has anyone had experience with these on the flathead 6s? What do you think would be better to use between the Dorman bolted plugs or rubber expanders?
I hope I only have to do this one more time!