Ground Controls item ARE what people race with. But I know your a racing connoisseur, so I'll let you tell people whatever you want. The skunk 2's have been used to race, but I've never of heard instances like you're talking about, granted I never bothered looking either, but from the people I know, they didn't have those problems. Maybe it was caused by the instalation, or even wrong parts?? I dunno.
Again, I'm not really supporting sleeves that much, just pointing out that there are a lot of older cars using them to race (yes, same Ground Controls we would buy), with good results.