What valve springs?

Im getting ready to put a forged bottom end in my GT and I am going to put those same springs on my stock heads and cams for now so I can hopefully get a little more HP out of the combo ......gonna up the boost to about 12-14 lbs once the forged bottom end is in and just put those springs on the stock heads , hoping it will make about 450-480 rwhp , made 385 rwhp on the stock engine and 10 lbs , but I spun a rod bearing last week .....