Am trying to id a GM camshaft I ve taken out of a 76 350 engine. The only markings I could find on the camshaft were: D27;GM32; and the last 4 digits of what I believe was a part number which are either 3930 or 6930. Can someone tell what this cam is originally out of and/or what the tech specs on this cam is?

I believe that is a updated version of the old -929 cam. I believe the specs are the same as the -929 but it is slightly retarded for emmisions reasons. Most likely the factory cam.

I am not familiar with the 929 reference. Is this a GM parts ID? Also if it is that cam how can I find the specs on it such as lift, duration, etc?

The 929 is the part number, the 930 is the casting number.
Don't pay any mind to seat numbers, Chevrolet rates the cam way too big, anyway.
At .050 it is about 195/203, and valve lift is .390"/.410", and it is on 110 LSA, I believe.
There are several million of those cams out there, Chevy used it for about 20-25 years.
It is available everywhere, besides at Chevrolet.

UDHarold