That’s second gear nowhere near third, I’ll post a pick.

I’ve only had second gear for about 2 months drive it everyday still just keeps on trucking.

I would say 3rd and don’t waste your time changing the shift solenoids if you don’t know the service history of the trans as when you get it done and refill you will likely loose all the gears just have yours rebuilt if you plan to keep the truck unless you can find a proven rebuilt one on marketplace or something similar.

Your glove box should have a sticker with codes on it. GT4 is 3.73 forsure.

I’d say your in 3rd I drive my sierra in manual mode I’m right around there in 3rd.

Probably lost 4th and ability to lockout 4th, so you’ve got up to third with lockout on third, next to go will be second probably, and you can run decently up to 60 with first, third and lockout, but you need to get over twenty in first to skip the shift to second. Went thru this with my Roadmaster with 4l60e.