I'm guessing that you already know about this or have already seen it or both, but I found this on moparts:
VIN OB 249307 GW340P34220701 RARE HARD TO FIND !1970 T/A BLOCK AND MOTOR PARTS. CASTING #11-24-69 BUILT BY NIGHT SHIFT AT 10:00 .020 OVER BORE BLOCK,318 STEEL CRANK, CORRECT 340 BUSHED RODS,WINDAGE TRAY,OIL PAN AND P/U.TIMING COVER AND BALANCER,CORRECT PULLIES FOR CAST IRON WATER PUMP AND CRANK BAKANCER.CALL CRAIG FOR MORE INFO 419-989-5027 PRICE $3500.00 OBO PICK UP OHIO OR WILL SHIP.