996 Engine part code? - 996 Series (Carrera, Carrera 4, Carrera 4S, Targa) - RennTech.org Forums
The only way you will know for certain if your engine number matches the VIN is to get a Certificate of Authenticity from PCNA for a fee of somewhere around $100 bucks. I am ot sure why you hit the panic button though. Porsche replaced so many engines during this run of cars that the original engine in the car is not necessarily a good thing. If you have a 3.6 core being sleeved to fit 3.8 pistons with the IMS upgrade, THAT is your talking point (and selling point if you choose to sell). The question to ask your builder is if the core is a 3.6 from 2002, 3 or 4.
The link above should take you to Renn-Tech and you can follow the instruction to get the general info for your engine but the last 6 didgits will be engine sequential serial number. Your 02 engine should start with M96/ so don't confuse it with the part number.
edit: just read between the lines and think your talking about the 'meister'. Get your bits back and send it to Don at EBS in Reno for a proper rebuild.