273 to 440 swap

I dont think either the 383 or the 440 will make that much difference when doing the swap. One is a bit wider and taller but from my reading the header clearance is just a bit different with the 383. As for power steering i dont think there is many headers that will accomidate PS. I know the Pro-Parts headers do. If you havent been over already go over to bigblockdart.com and browse there tech section.