I wouldn't be so sure you know. Driven a few skylines and thought the outright power might be more, the response on this zed is amazing!!!!!!
Then why change?
My 34 is a lot quicker than my supercharged Z was (Que your LOL HKS was slow )
Its an early JDM with 80K+ miles, its worth maybe 6K at best in N/A form. I'd say around 7.5-8K max for it with the supercharger fitted. Also your front bumper needs a respray badly
You will make a @*!# load more money by breaking it, trust me. Been there, done it, bought the Skyline