94 Mustang GT convertable weighs 3,452 lbs, has 215 HP, and 285 Ft-LBS of torque. Your Eclipse stock weighs 2754 lbs, has 140HP, and 130ft lbs of torque. Now you say you have a cai, udp, and exhaust so we will be generous and say you are at 155 fly wheel hp. That stang has 60 more HP and over twice the amount of torque which is what is going to get that heavy ass car moving fast. He is going to tear ya a new one from a stop with all that torque and you won't have enough hp to catch him either. That's if he is bone stock, minimal mods will bring the 5.0L to life real quickly. I will have to agree with ivaznGST that you will get raped. Sorry man, but reality is a bitch

99GSX Auto 14b@17psi 13.345@102mph