What are these two plugs?

Is the sump on your "new" engine in the back or more centered?
Yeah even the A bodies had different pans up to 66 and after 67. There was a long thread about this courtesy of member "cruising ram" on here recently, it shouldn't be more than couple of pages back. There was a pic in there showing all the different pans that could have come on a/6 and description of which ones could/couldn't be used in a given chassis. Would be worth a look back for you,
at this point.
If you have to change your pan for your replacement engine to fit your car you also need to make sure that you get the right pickup screen that works with that particular oil pan.
If that engine is so nasty/dirty, are you planning on going thru it to any extent before you drop it in? I'd at least do a complete regasket on it and a power wash before dropping it into another vehicle.
Do you have any history?
If your car is a 65 and the engine is a 68 or newer you need the adapter sleeve to go in the back of the crank for the torque converter snout.