I can relate, because there's a similar TT in Austin that I use as a benchmark quite regularly... Similar temperatures, etc. I get a little bit more scientific when I run this because I use an SRM for pacing, but hey... It applies to everything.
Don't bother drinking, first off. 8 miles is too short. You're gonna be thirsty at the end, but that's OK. I did this last week in Austin -- 98 degrees during the run, and was fine without a drink.
Because this is a shorter TT, aerodynamics matter more since you can push harder. Try and get as aero as you can stay for the whole time... It'll help.
As for pacing, do this. Go out at a pace you feel like you can hold for about half an hour. It may feel easy in the beginning, but it won't later. Keep this up until the turnaround. Once you hit the turnaround, ramp it up pretty significantly. When you're about 1/2-2/3 of the way back, just go for it. Don't look at a HR monitor, speedometer, anything. Just GO as hard as you can. You shouldn't have anything left at the end. My rule of thumb is that if I have enough in me to sprint for the line, I probably could have gone harder.
Hope that helps!