Brought Home A Parts Truck

[67chevy1]

I brought home a parts 67 for the cab. It needs some floor work but everything else with the cab is in pretty good condition. I fiddled with it for a little bit and it fired up. It needs a fuel pump because I had to bottled feed it. I might just put a pump in it so I can say I have driven a 3 on the tree. Now my question is what are the tale tale signs of which inline 6 it has in it. I don't need the engine but would like to know which one it is.