No 318 cranks are drilled through the journals due to the smaller rods and piston lighter weight.
Crankshaft
The 273,318 and 340 all have the same stroke and use the same crankshaft. There are , however , several different crankshafts available. The 1968-1972, 340 engine used a different crank(PN2843868) than the 318 although both were forged. The 318-3 truck crank (PN 2843885) is a forged, hardened crank, but is no longer available. The 1973, 340 uses a cast crank (PN 3751162)and requires a special damper and flywheel or torque converter assembly. Do not use forge crank flywheels,dampers, or torque converters on cast cranks vice-versa. All 360 engines have cast cranks with larger main bearing diameters(2.81") than the (2.50")of the standard 318 or 340.