A BRAND NEW 1978 413 BLOCK. IT HAS NEVER BEEN USED AT ALL. THE BORES ARE BRAND NEW. IT IS BELIEVED TO BE A US FORCES POWER PACK BLOCK FOR MILITARY VEHICLES. IT IS ALSO A HD BLOCK FOR COLD WEATHER. THE SIDES OF THE CASTING HAVE EXTRA WIDE WEBBING FOR REINFORCING. I HAVE MEASURED THE BORES AND THEY ARE STOCK AT 4.18 inch’s.

IT NEEDS A 70 thou BORE TO MAKE 426cid ENGINE. OBVIOUSLY THE CASTING WILL HAVE TO BE ULTRASONIC TESTED TO SEE IF IT CAN TAKE THAT OVERSIZE.

I DO HAVE SOME VERY RUSTY AND DAMAGED 413 HEADS. I THINK THEY COULD BE RESURRECTED WITH SOME GOOD QUALITY ENGINEERING.

THEY ARE NOT MAX WEDGE HEADS. IF YOU WANT MAX WEDGE HEADS AND PORTS, THEY ARE AVAILABLE AS BARE, PARTIALLY MACHINED CASTINGS FROM MOPAR.

THEY WILL ALSO NEED ROCKER SHAFT SUPPORTS TO BE MANUFACTURED, AS THEY WERE NOT CAST IN, AS IN LATER HEADS