In 1969 the SS396 as a series was dropped and the 396 engine was relegated to being part of the RPO Z25, SS396 option. The 1969 model year is also the ONLY year to offer any SS Equipment option on anything other than the V8 Malibu sport coupe, convertible, and El Camino. For 1969 ONLY, the Z25 option could be ordered on the V8 300 Deluxe series 2-door coupe (13427) and 2-door sport coupe (13437).
Since the SS396 was relegated to an option and stopped being a separate series there is nothing on the Fisher Body Number plate nor the VIN to indicate the car was born with the Z25 SS396 option with one exception. Two exterior paint colors coded "72" for Monaco/Hugger Orange and "76" for Daytona Yellow were paint choices ONLY when the SS396 option was ordered. These two colors were certainly available on other 1969 Chevelles but did require option ZP3, special paint, to be ordered. When this was done, the trim tag would not show the "72" or "76" paint code but rather would show a dash character (-) in the appropriate lower or upper paint code position. Be alert for fake trim tags that may have one of these two paint codes added to "prove" the car is an SS.
The only way to truly document a 1969 Chevelle as having the SS396 option, aside from the two paint codes mentioned above, is with some sort of paperwork showing the option itself or the engine suffix code and the car's VIN. Examples would be the build sheet, Chassis Broadcast Copy sheet, warranty card Protect-O-Plate, or an original factory stamped engine where the partial VIN stamping is a match to the car's VIN sequence.
http://chevellestuff.net/1969/69ss.htm