how much horsepower can you get out of a celica gts engine?

to general of a question....if you built the motor top to bottom and sleeved the block u could run over 20psi of boost and have an ungodly amount of power....but it would cost a ungodly amount of money

stock motor with bolt on's....maybe another 20whp over stock....
stock motor with turbo...add another 60-80whp over stock....