Both the 12:1 and the 17:1 are power steering boxes. The 12:1 is from 73 to 75 and the 17:1 is 76 & 77. The 12:1 is supposed to be 5.3 turns lock to lock and the 17:1 is 3.8.
An advantage of the 12:1 is it is close to the original quick steer box with a 12:5:1. This is said to be a great feel for a steer box, but I don't know if being close to the same ratio will yield same feel with a different box. On the other hand the 17:1 box is the newer model and hot rod suppliers seem to sell lots quick turn boxes which makes me think the 17:1 would be a better choice.
1) Are there any down sides to a quicker box?
2) If I can buy both boxes for close to same money, what would you all go with?