As others have stated, it depends on options such as 4wd vs 2wd, disc vs drum brakes, and gear ratio.

A 2wd axle will not fit properly in a 4wd truck, nor vice-versa.

You can swap from a drum brake axle to a disc brake axle, but you'll need to replace the park-brake cable as well.

If you're vehicle is 4wd it is critical that you find an axle that is the same gear ratio as your existing axle to match up with the front differential. The easiest way to find your gear ratio is to look at the RPO code sticker in your glove box. Look for one of the following codes:
GU5 = 3.23
GU6 = 3.42
GT4 = 3.73
GT 5= 4.10

Also FYI, the code G80 means the axle has an automatically locking differential. For mild off-roading this can be an asset.