I must be out of the loop because I didn't know you picked up a LS1. Those times are pretty decent assuming you're bonestock. I do find it interesting that everyone says the LS1 is good for low 13s bonestock (auto or 6 speed) yet most Kansas/Missouri guys get high 13s/low 14s for stock. I think that says something about our tracks.
Anyways, I use to own a 94 Z28 auto/2.73 gear and I managed a
13.9@99mph with a 2.0 60' with just a catback on a frigid night at KCIR. Later on I added an intake, chip, y-pipe, light 16s, light driveshaft, and ignition and got a
13.4@104mph at HRP in Houston. My best at KCIR with that setup was a
13.6@102mph or something.
I regret not holding on to the Z28 longer, but it's build quality forced me to sell it. I should have done the cam, heads, stall converter, drag radials and I'd be looking at lower 12s. My friend has a 96 with those mods and the STOCK converter and he's getting
12.4s@109mph at KCIR!!! Get a stall converter, headers, and drag radials and you'll be looking at deep 12s. The autos are the only way to go when it comes to the 1/4 mile.
Dave
The temp was great 
Nice and cold. The track didn't hold that good 
Nitto equiped car were having issue's hooking! 2.0 60's!!!! 
Nothing more than custom catback, Pully, Power programmer. That should yeild me into the 13.6 area for sure! I am even thinking a Cat Deletion 