VIN explanation help

I purchased a '72 (build date of 8/71) Chevrolet G20 van with 15K original miles. The owner told me that it was a 350 cu in/TH350 engine/drivetrain configuration.

A friend of a friend looked at the VIN and said it's a 305, not a 350. I have looked at several VIN decoders and the digits are not making sense (don't seem to be in their proper locations).

Can anyone help me determine what engine this is, either by VIN or some other method (stampings on block, etc.)?

Thank you for your time and consideration. Rob

What's the VIN?

CGE252U103346

Thanks for taking interest.

Ok, here's the deal. That VIN only denotes that the van has a V8 engine "E". GM didn't use the 305 till 1976. So, unless it was swapped, it most likely is a 350. Lots of good info here..http://en.wikipedia.org/wiki/Chevrolet_small-block_engine. Yes, block stamping will tell you for sure, usually stamped on the front of the cylinder head.