That is for a POWER steering car. And will not fit an A-body with any type of headers. Very very hard to fit with 340 manifolds, but I have seen it done. Needs custom drivers side headpipe and patience.
A C-body centerlink will not fit an A-body.
Now, I realize the original poster didn't say he was looking for manual fast ratio box. But in 1968 the only option fast ratio steering was manual.
