Why do you ask ?
If you want to buy a grey top , go for it. Put the Red Top exhaust , put a LSD 5 speed .
Paint the inlet RED . And wire the ECU properly and you have a RED TOP.
For the nitty gritty look at the reference PHEONIX has composed..
You want it to look exactaly like the red top be prepared to spend 3 times the value of the clip.
Do yourself a favour get a Celica Red Top