This is the only thing that'll make the Celica faster than what it is. (Well this and nitrous oxide).
Without it, you are looking at best mid 13 seconds.
From the look of your posts, you seem like a young cat, right? Please do a search about what's available for the 7th gen Celica before you say things you shouldn't.
This site contains tons of info, please utilize it and search for your answers.
The 545 was whp indeed, I wasn't sure that's why I said "if I'm not mistaken" which in this case I was. But then Smaay's is a built stroker that initially made 545 whp and 406 wtq, I think he's sitting higher now.