Please put away the 1/4 and dyno calculators, those aren't gospel. I've had dozens of cars of varying power levels, and I'm a little suprised it didn't run quicker than 125. Here are some other times I've run:
98 Firebird, 400 rwhp 346ci, 3600 lbs, 120 mph
98 Firebird, 440 rwhp 382ci, 3650 lbs, 125 mph
98 Firebird, 525 rwhp 434ci, 3650 lbs, 130 mph
05 Corvette, 505 rwhp 364ci, 3550 lbs, 130 mph
69 Camaro, 500 rwhp 346ci, 3600 lbs, 125 mph
Gearing, aerodynamics, weather, area under the HP curve, etc... also play factors in trap speeds. 125 mph is pretty common for a stock C6Z06 in the hands of a capable driver. I'm not sure why you cannot just accept this fact. Look at my 382ci combo Firebird above, it went the same trap speed with 300 more lbs and the same power.
I get my results at the track, not by a calculator. Here is an old vid, circa 2001 or 2002, of the 434ci LS6 smallblock combo I had in my blue Firebird. 6-speed manual car with A/C, leather interior, no weight removed. 129 mph trap speeds at 3650 lbs with 525 rwhp. Finals at a national bracket event.
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