Good race, you should have no problem annihilating a near stock 95-98 gt. I think you'd probably pull a 99+ gt pretty good too. As to the 12.9... that's probably a little too optimistic. Not saying your car doesn't run it but I have an AOD and with your mods I'd think you would be running more around 13.4-13.7, especially without a converter. Not saying you don't run 12.9, it's possible though. Get it to the track and find out.
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92 AOD GT, K&N, ram air, pulleys, 2 ch. flowmasters, 4:10's, shift kit, 1 5/8 mac longtubes and offroad hpipe 14.249 @ 97.34 mph before the headers and hpipe