What headers will fit???

I think fixing it will fix the steering box issues. The middle of #3 pipe is right at the corner of the box. Move it forward and inch and the corner of the box should sit between the #3 and #5 pipes, and the #3 pipe won't be trying to fit the largest diameter part of the pipe past the widest part of the steering box.

I'm still not convinced those conversion mounts are putting the engine in quite the right spot though.