I have a custom 62 300, the power steering pump is leaking. Is there any other pump that will bolt in from another year?
I do not care about stock, the car is a full custom, running a 1970 440.

 

Since you are running a 1970 engine already, you should probably be looking for a 1970 (or so) pump to bolt on to the engine. Most probably, Chrysler didn't specially design and build a power steering pump but bought it from a supplier like Saginaw Steering (GM) or Borg Warner or somebody like that.

I would search for classic Mopar parts on the internet. Even places like Rockauto.com carry power steering pumps from that vintage. You might have to order it and then see if it will fit. You might also need to have some hoses made up to connect.

You might want to see if you can find a shop that will rebuild or repair the old pump with some new seals.