You're exactly right about the LS-1 appearing in '98 F-bodies and '97 Vette's. You're also right about the LT-1 producing more low-end torque (peaks about 2500 RPM) while the LS-1 delivers more HP on the top-end.
With street tires at the track I've found the low-end torque to be a disadvantage because it's difficult to get the radials to "hook-up". All that low-end torque hitting the rear wheels before the weight shifts back onto them yeilds a lot of spinning off the line and a bark as the car shifts to second. I've still turned-in a 13.9 quarter mile with cheap street radials.
I've ordered a set of Nitto 555's that I hope will shave-off a few tenths and actually let me take advantage of the LT-1 low-end torque off the line. Hopefully I'll find-out next week!