I think a few months ago, someone on this forum tried ramshorns and said they still had to move the steering box. But I don't know. Seems like it should work.
I would think a header would work too, if you are capable of cutting and fabbing up your own primary tubes just where the steering box is. Shouldn't be too hard. It just depends on how tight it is.
Has anybody tried mounting the V8 engine and transmission slightly to the passenger side instead of dead nuts in the middle? If you have U-joints on the drive shaft, a very slight angle shouldn't matter at all.
I believe in the 60's and 70's, Corvettes had their engines slightly off center...possibly to clear the steering box on those cars.