so my first car is a 1987 nissan sentra hatch, I am interested in swapping it and have settled for the sr-20, Im aware that engine swapping is illegal. I live in california and cops here are crazy any tips or is there a legal version i can swap in?

you can try some of the California auto repair (http://www.automd.com/shops/CA/) if they willing to swap for you... but I guess they are...

If that's illegal you can't do anything but to follow the rules, I'm pretty there are some other option.