Headers arent fitting. Power steering pump in the way. Which way do I go?

There were several power steering pumps over the years. Maybe a Saginaw pump from later engines sits lower. For example, I pulled a bracket from a Volare slant that mounted both a Saginaw pump (on sub-bracket) and Sanden AC compressor. That pump sat far from the engine so shouldn't interfere. I got the bracket for AC (manual steering in my slant). That bracket could serve to support a turbo-charger later, which would look nice with your headers. Probably more Aspen/Volares in junkyards than Darts.

Manual gearboxes command a premium since more desireable. Used ones sell for $50-$100, usually w/ Pitman arm. Any A-body box thru 1972 should fit your 1963. At least they fit 64-66, but 63's might differ a little.