I've got an interesting one for you. First some backstory.
Picked up a '77 Continental this past November. Really decent shape, with a claimed 117k miles on its 460. Right after bringing it home, I noticed a strong smell of gasoline that always seemed to surround the car. Soon realized the mechanical fuel pump body had a rupture in it, causing a geyser of fuel to shoot upward, and would then get blown back onto the carb by the rad fan (which made it seem like the carb was leaking initially, at least until I caught the geyser in action). Bought a replacement pump at a local auto parts chain store, had it installed at a local garage, and all was well. Or it was, at least until Christmas morning, when the engine died in the middle of an intersection. Had it towed back home, where I tinkered with it in the driveway a bit until the weather got cold. Thought it was a spark issue at first, but then realized the distributor wasn't turning. Pulled a valve cover and found that the valves weren't moving either. Crap. Must be a broken timing chain.
Anyway, that's where it sat until a few weeks ago when I had the time and garage space to tear into it -- but up to that point, I was still constantly doing research as to what could have caused this, going through forum post after forum post trying to figure out why the chain would have broken. Once I had it in the garage, as I got deeper into disassembly, I started to see some pretty bad signs. Like the timing cover behind the water pump having a massive crack in it, which looks to have been made from the inside (see pic). Once I got the timing cover off, I realized the extent of the damage. No, the chain was not broken. The cam was.
So, about that research I had done earlier, there was a thread I discovered
that stuck in my mind, since I had replaced the fuel pump only shortly before the breakdown. Given everybody's response to the verdict in that thread, I figured this mode of failure was a pretty unlikely possibility, but it bothered me enough to ensure I checked the fuel pump when I removed it.
And, lo and behold, the arm had indeed snapped (see pic). Looks like it got kicked up behind the cam sprocket, wedged itself in, and snapped the end of the cam off (see pic). I don't have a picture of the end that snapped off for whatever reason, but it did sustain some serious damage from the gear, and as the image of the cam shows, it also broke that circular plate holding the cam in place (not sure what that is called).
I'm in talks with the store that sold the pump, who is working with their vendor, to hopefully get the repair costs covered due to the clearly faulty part... I mean, it was only installed for a couple of weeks, and per the mileage documentation, went all of 161 miles before the failure. So it was indeed installed properly and was working, just not for very long. At the moment I'm waiting to hear back from them about the next steps.
Anyway, I've got about a million unanswered questions about how this is going to work out. But one thing that has come up a few times is that the customer service agent from the chain has been insisting that the 460 in this car is non-interference (with the implication that it wouldn't need any head work). But everything I've found, including many of those responding to the linked post above, seems to indicate otherwise. I can verify the engine is original to the car, with the stock D3VE-A2A heads. So just to confirm, the engine is definitely an interference design, correct?