1974 Dart

The begining of the list is just basic and I know where I can get them.
I need an easy way to find an oil leak. I think that it is leaking from the manifold gasket. It is not a major leak but I need to plug it. I know that I need to replace the dash. I also need to either replace the carb or rebuild the one that I have. Is it hard to switch from a 2 to a 4 barrel? I bought the car two days ago I haven't got an entire list yet.