Porsche 911 Performance Handbook - Bruce Anderson - Google Books
Scroll down to page 44. You will see a picture where the engine serial number is (the one you found) and to thr right side and behand it, you will find the engine type. This will tell you what you have.
Also, I suggest contacting the PCA (
Porsche Club of America - Home) and request a Certificate of Authensity (COA) It costs $ 150, but you will have your car's build date, options, engine and trans serial numbers. Nice to have to. Both of my cars have the COA.