I ran 12.1 at 122mph all day long when mine was turbo, that was on street tires on a unprepped track, 350whp. Was hanging out for a 11 one day, it had the power, just not the traction. The viscous lsd was spinning one wheel to about 3/4 track, but boy did it pull once the other wheel hooked up. But, then at the strip one day it got a small oil leak on the turbo feed on the block, i drove it home and pulled the engine and sold it.