Blah Blah Blah Blah...... same old story
Arguments that cant really be solved. I have no idea what a stock 99gt is going to do so I am not going to post any numbers for it.
I own a 99 Lightning with a 4# pulley, Diablo chip, JBA headers along with a custom exhaust catback, and a cone K&N yes that is a modification. I dont know why you cant call it a mod. Is it a modification to the stock form? YES My truck puts out around 425hp, and gets no grip. HEHE
Really unless you get a power adder I dont see you beating a modded Lightning. But you could be able to beat a stock lightning with just a couple of bolt-ons.
I think you might be a little closer to the lightning from a roll. As i notice in my truck. It just doesnt have as much go from higher speeds, But damn are they torque monsters!