Just thought I'd chime in here...
LS1's often (in the right hands) run mid-13s bone stone, and are easy to get into 12s with minimal mods.. like, and airbox lid and a cutout will do it. As someone mentioned, the Formula is often faster than T/A, et al b/c its a little lighter.
Off the line tho, I would give the race to a SyTy b/c with so much rwhp its tricky to hook on street tires. Depending on what mods your truck has tho, on the top end, the LS1 will have a decent chance to catch up with you..
Just ask Christian.. I hear he met a friend of mine with one of those minor-mod'd T/As running 12s at OSW this last week.
*smile* Anyway, let the arguments continue
-Heather