Aren't the 96-98 GTs considered the turds of the mod motor era? 1996 was the first year for the mod motor into the Mustang and they were 210 HP... Power got bumped to 260 in '99 with a heads and intake redesign. I think you should have beaten him with the mods you say he has done to the car. The only thing I can think of is maybe he had the PI heads and intake swap done or maybe the previous owner of the car did??? I would like to think a GTP can hang with or even edge out a 96-98 GT all day long, stock for stock or slightly modded either way.