Questions about mustangs?

alright heres the thing, i have a 2000 pontiac trans am ws6 automatic with 150,000 miles and slp lid and flowmaster exhaust. i also have a rebuilt tranny with changed shift points so it shifts faster and harderi also have 555r nitto drag radials. my buddy has a 2002 mustang gt 5 speed and it has a new suspension, throttlebody spacer, cold air intake, headers, flowmaster exhaust, 373 gears and a programmer, and brand new tires. his car weighs around 3300 without him in it and mine weighs 4279 without me. but i also have two subs and an amp in the car to add weight. alright so we raced from a dig and i beat him by 2 21/2 cars. he made up excuses and said he can beat me from a roll and so we started at 35 mph and took off and i had alrede beat him by the time i got to 70-80. so then he says race my new dodge 1500 cuz it has the hemi and it doesnt spin. i said ok and i jjust straight up left him. who coulve guessed. hes so upset bout loosing that he went and put a chip and a 100 shot of nitrous in his car. hes already used one bottle and i told him hes gonna mess his car up but he said he dont care. he hasnt asked to race yet and my other buddy thinks its cuz hes scared he will still lose and then what will he do? <<<< (idk about all that) he said if he beats me to tell him to take the nitrous off and lets see how the race should really go. but he also said if he beats me now then it proves nothing cuz a highly modded car needs nitrous to beat a older basically stock car. but i also look at it this way he has 1000lbs less then me and more modds. im basically stock. and my 323 gears are messing up. what do you think will happen if i race him now?