Earl:
Nope, no explaination has ever been offered to me, but this certainly isn't the first I've heard of it. The quote that TKAMIYA gave would be a 104 engine, not a 103. A 103 should be less.
It's almost common enough on 103 and 104 engines that you can almost catagorize these engines into 2 basic groups, those that have blown headgaskets already and those that will shortly.
Gilly