Oh ******.
I spent a good 10 minutes trying to remember which engine was in the Malibu. Shows you I get no points for my memory. Looks like I was 1/2 right - the Lycoming is in the Mirage, but I think they introduced that engine to fix some of the reliability problems they had with the Continental engnie.
Well anyway, the point is still a valid one. I'll see if I can remember some other aircraft with a TSIO-520. The A36TC and B36TC spring to mind, and they suffered from poor reliability too, until the cooling problems were fixed in later B36TC's.
Bevan..