questions

[itsjustsway]

Ok so I have been doing a bit of research nd have read some interesting things. I hear nd read about "stock" 7mgte reaching 400 rwhp. My question is how is this possible if the car is stock? What upgrades need to be done? I have a stock 7mgte nd recently replaced the head gasket, I have a 3 inch down pipe, nd exhaust. I'm currently in the process of making a cold air intake.. I understand the car is old nd needs TLC .. Oil changes hard maintance ECT. But how can I reach 400-500 rwhp nd making it able to run as a daily driver.. Around how much will be spent in upgrades? Another route is just buying a 1j nd building that but will it be a waste of money seeing as how I can work with what I got?
If you got this far thank you for reading im just trying 2 learn nd spend my money correctly instead of taking short routes nd wind up 3 steps back instead of moving forward.