Looking For Matching Numbers on a 1972 Corvette

I'm kind of new at this, but I'm really looking to buy a 1968-1972
Corvette. The one I'm currently looking at is at a dealership. It's
a '72. The dealer is trying to tell me the 98k are original miles.
I'm pretty sure he's wrong. I know that the last six digits of the
VIN number from a corvette are stamped somewhere on the block. I've
heard that the late 60's models have a metal pad tacked on to the
block on the passenger side just below the cylinder head. But where
do I find it on a 1972?

Any help would be greatly appreciated.

Thanks,

Dave

On the deck, in front of the right side head. Make sure, especially if
your paying the premium price for matching #'s, that they are indeed
original. If they look mis-spaced or crooked, they may have been put
there by someone other than the factory. An old trick ya wanna be
aware of before emptying your bank account. Good luck.