1957 Chev, lady owner needs help !!

[Pooseys]

Hi guys, so my dad past away and left me his beloved recently restored truck. On his last drive it decided to throw a piston. I had a mate take motor out and I bought new pistons and rings, bearings and new crank. Now heres where I get stuck. I need to find some new frost plugs, and also 2 keyways for the new crank. The motor is a 235 shiftmaster, straight inline 6, right hand drive. Any help that you guys could advise me on would be bloody awesome !!!! Thanks in advance.