To start, Your car could NOT be a SS Big Block car with an X11, It could be an SS 350 car though. It also could have been a COPO Big Block, but with that VIN, it is doubtful, even though it is in a time span of COPO builds. I won't elaborate anymore at this time. You need to read this:
http://www.camaros.org/model.shtml and then you will know more of what to look for. There are so many clues, but with so much done to your car, it would be difficult as those clues may be gone now. Only a small % of X11 cars are SS's, so what you ask may never be known and the probability is not in your favor. After some reading, you will know where to look for clues,such as a "muncie hole" in firewall or 'exhaust hanger" on L. rear frame rail. Just saying, you will have to do your homework before anymore can be said about your car except it looks to have been done well. You did say,"you wanted to educate yourself"? That is my best advice.