Verifying block year for Head Bolts/Studs

[BR3W CITY]

Since I've got a massive stack 'o' parts in the corner, its about time I get around to ordering some ARP head bolts so I can do the new heads I've had on the bench for almost a year. At some point in 2004, GM switched from a variable length set of bolts, to a single size of head bolt....the problem is knowing which one you need if your ANYWHERE near the switchover point.

My block is a 12553164, which is the standard iron block made from late 98 into 2004. It was from a 2003 fleet van (and vans in general could come with a weird array of last-years and next-years parts)...

The front passenger side of the block has "2162", which if I understand means "February 16 2002" casting date. Is this correct, or did I miss-indentify these numbers?