Going to need more info than that.
Like where do you plan on buying your new transmission ?

 

I’m not sure where we’re getting it yet. We got the one for our other truck at O’ Reilly’s. My truck is 1999 Chevy Silverado LS1500 2wd 5.3L. I’m reading it’s the 4L60E. I know I’m sounding completely stupid right now, haha. Lack of sleep.

 

Amanda, it refers to the strength of the transmission.
In the auto transmissions it's the different shift kits.
In the manual transmissions it's actually the clutch, that is, different grades of clutch.

Look at it this way, stage one is your truck from the factory,,
Stage 2 is for performance, a corvette street racing, or medium weight towing.
Stage 3 is for heavy duty towing, or 1/4 mile racing

 

Ok that makes perfect sense to me. I myself would go with stage 2 provided I don’t have to change anything else.

 

Stage 2 will give you a little harder shifting, you'll feel it when it shifts. But, it's great if you tow a trailer or dive it like you stole it.

 

No towing but tend to dive it like I stole it, lol.

 

Depending on the rebuild company the stages are different. Ask them what their ratings are. As an example, my stage 2 is rated 600HP which shifts hard and fast. Be careful who you buy it from, places like Monster Trans and Trans Depot have a poor reputation. Gear Star is more expensive but a quality builder - just saying