1970 Chevelle Engine Photos

Can you spot the differences in these Tonawanda engine stamps aside from the different dates and obviously different suffix codes?

02/01/2009
T0212CRR

02/01/2009
T0213CTX

02/01/2009
T0219CRT

File Photo - 08/31/2009
T0325CTW

05/16/2010
T0622CTX - note broach marks