Well "as low as I can" is a loaded question! Most trucks (both short bed and long bed) can get 2,341:1 if they so wish, but as we all know that's just crazy
No matter what you do, all Marlin Crawler low range products do not affect the driveability on the street. Our low range products do not affect your vehicles high range, which is 1:1.
The real question would be, what do you plan on doing with your truck? If its just for some mud or snow and playing around, then you'll probably only need about a 100:1 or so ratio. This can be achieved with a dual case or a single 4.70:1 gear set. Or if you want to be a bit lower, around 223:1, you could use both a dual case and a 4.70:1 gear set. We call that an Ultimate Gear Ratio.
Other options are using a dual case with TWO sets of 4.70:1 gears, and that'll put you around 400:1.
Or you could run tripple cases, about 247:1
Or tripple with a 4.70, about 510:1
Or tripple with two 4.70s, about 1047:1
Or tripple cases with tripple 4.70:1 gear sets, about 2200:1
BTW, what year is your truck? If its a long bed extra cab with a two piece rear drive line, I bet you could muster 4 cases, although this has NEVER been done. Wow, a quadruple case, then try that with 4 sets of 4.70:1 gears, and ya got 11,005:1
