how much is possible on a stock 400??

[93b18civic]

i have a 01 400ex and have installed a wb e-series slip on, wb air filter, sparks key. is a hotcam stage 2 and a 450r carb too much on the stock cylinder/sleeve? or should i be good as lon as i jet it properly? any side effects? i ride year round and it gets -25 degrees here

any insight would be awesome