trying to figure out weight(approx)

on my 97 cobra, the door, says 4321, I think. I tried searching the forums, but decided to go with 3650 lbs. I have been wanting to play with my gtech, but never knew the weight to use it. I know the h pipe is considerably lighter, the driveshaft is lighter, my rear sway bay broke, so I haven't replaced it yet, and the wheels and tires are heavier. anybody have an estimate? With my wife in the car with me, I know to add around 235 pounds. what about gas, does it weigh about the same as water 8lb per gallon? any help is appreciated. Thanks chris

using that weight 3650, with my wife in the car, on a 1/4 tank of gas, with a half a## launch, and run up to 60 and let off, I was watching, I was in a 40mph zone, it said 5.67 0-60, sound about right???