2YABC6303 is a 460 crank, '68 to 78 6303 is the part number to add.
460 68-78 2Y 2YA 2YAB 2YABC Stroke:3.85 Main Brng:3.000 Rod Brng:2.500
Rods are C9AE 1969, Full-size/Galaxy, engine part
Should be C9AE6200 for full part #
Here's 460 specs. Measure the pistons & see if they are 460 -- .030" oversize.
460 -- Bore & stroke 4.36" x 3.85" Manuf years.- 68-80+ Bore spacing 4.90"
http://raceabilene.com/kelly/hotrod/engine.html