Which steering gearbox is for me?

Frnknsteen said
1. Which ratio did you choose, what kind of driving do you do most, and how do you like it?

I used a 20:1 worm in my original box until I bought one with 16:1 worm. For slaloms, less turning of the steering wheel makes it easier to keep on top of the situation.

2. Is Firm Feel the only one that uses the factory case?

I would guess that steer and gear as well as most others use a factory case; Just not Borgesen or Flaming River.

3. Am I correct in thinking that the Formula S cars came with the 16:1 ratio?

Listed as a seperate option (see for example: http://www.hamtramck-historical.com/images/dealerships/DealershipDataBook/1968/68_Barracuda0016.jpg)

I have Tri-Y headers and my current box fits nicely, but I don't know how an aftermarket case would fit. I don't want to have to start changing other things.

The amount of force required to move the steering wheel will depend on weight, tire width, road surface, caster and speed. Low speed (parallel parking), high caster, wide tires, heavy front will all require more muscle effort. So if you have a big block with +3 caster and 245/50r17 and need to parallel park, you'll need to be in good shape to be OK with the 16:1. A basically stock setup, small block or slant, +1.5 caster or less, you'll notice the effort parking but your petite gf may not like it unless she works out.