Filled block on the street?

In discussing the filled block question with a guy I have known for years, I just discovered that he short filled his Pontiac engine several years ago. He drives in on cruises and poker runs all of the time. He drove it to Denver, a 350 mile trip, to race at Bandimere with some of his buddies and back in the middle of summer. Claims there is no issue with cooling but he does run a modern GM oil cooler. This surprised me because the first I'd heard of running fill on the street was the two Mustangs previously mentioned.