Spindle differences?

[tweet66]

Other than the spindle size itself what are the major difference in 66 vs. 70 mustang spindles? I have a set of each for my 66 coupe (lowered, R&P, Bullitt wheels) and I'd like to use the 70's but I'm worried about bad bump steer like I currently get from the Granada's that are on the car now.

 

[6Stang7]

The only difference I know of is that using 70 spindles on a 66 will require a different tie-rod end.

I have spindles from a 72 on my 67 and I don't notice any bump steer.