I'd look into using a '55 265 left side manifold and leave the steering box where it is. This tip was posted a while ago by someone who did it,and he says it works fine,and the manifolds are still reasonable low priced. Personally,I'd change both of 'em,just so they'd match. Remember,running mis-matched exhaust manifolds makes your truck go in circles.
Speed


1954 GMC 350
1957 GMC 1/2 ton
1962 Chevy C-30
1952 Chevy 6400 dump bed project truck
'98 Harley FLSTC
'66 Pontiac Catalina
'76 Chevy 1 ton Duallie
'84 Bronco II
'78 Dodge W-200
'81 Toyota 4X4 truck