Agreed Blackbird....their stock turbos are pretty small and he probably won't get a whole lot more out of them. I've seen a few BPU++ or so Supras in the mid-low 11's, but it's hard to say if they're the exception rather than the rule as so many people get so many different results. If you do any mods at all to your LS1 then it'll be a beast. If he ever does decide to go single turbo though watch out

That just means you'll have to slap an s/c on your ride and you'll probably be right back in front