I was looking to find a exploded view or cross sectional diagram of a full floating axle and came across a website that had some pretty good diagrams. These really helped me to visualize the difference between the two, without having to go to a wreck yard and pull one apart.
http://www.cs.odu.edu/~glaves/chris/axle/

Anyway, the writer describes a 3/4-floating axle, but doesn't show an exploded view or cross-sectional diagram. He describes the axle but I'm confused on where the bearing sits. Also, how common are these 3/4-floaters; i.e. what vehicles and years carry them? Is there a way to look at the axle and determine if it's a FF or a 3/4-F without taking the assembly apart?

I want to make sure I pull a 14 bolt FF and not some "old ball" 14 bolt 3/4-F. Plus gaining a little knowledge helps.

3/4 ton full floaters are very common. Prior to 1980, all 3/4 ton Gms were of this variaty. After that, they had a semi float 14 bolt. Ford and Dodge did the same with the Dana 60s.

No, they arent. Ive seen two in my life. 3/4 floating axles are are supported by the spindle but the hub is captured by the axleshaft. and in the case that Im thinking of (model B ford '29 vintage) a big nut. They are different than 3/4 ton axles.

Its a system that worked well when thier metallurgy and machining capability was poor.
http://www.autobook.co.kr/theory_practice/chassis_driveline/images/drive_axle_type.gif

The image sucks, but it helps. both of the 3/4 float axles that ive seen had two caged roller bearings in them.

Any 3/4 or 1 ton axle that you find under anything newer than say 1965 or so will be semi flaot or full float. 3/4 float axles were done by WWII. They suck. 14bolts came 2 ways. Semifloat ( you dont want this one) and Full float. You want the full floater with eight lug nuts and 8 more little bolts holding the axle flange to the hub.
http://www.off-road.com/jeep/tech/axle/float.jpg

a 3/4 floater will look like a Giant AMC 20 with a huge nut in the middle of the wheel. I'd be shocked if you found one of these.