If the car was made after 1/1/69 and has 2 fuel lines, its an SS. The only small block that used two fuel lines after that date was the L48. Both the L34 and L35 big blocks also used two fuel lines, all others had a single 3/8" fuel line.
SS's also required front discs, multileaf rear springs and for the most part a 12 bolt axle, although an L48 with a powerglide transmission would come with a 10 bolt axle.