Sides for dump

[Stafford Landscaping]

I'm wanting to build new sides for my 12ft dump. I need them about 2ft tall. But I also need them about 4ft too for mulch but don't want to run the 4ft all the time and I don't want to change two different side back and forth all the time. I was thinking of making the 2ft sides them making another 2ft sides and then when I need to haul much some how connecting the two together
but I need two make the connection strong enough to hold the weight of the mulch. If any of you have something similar if you could let me know or post a picture. Would be a great help.

[irishgoldcleanups]

rite now i have 3foot side on mine soon to be 6 foot with 18" tool box's at the bottom 9' long . with 3' doors on both sides in front. on back is a lift gate that handles 3600lbs. 3'x8' with 3' barn doors over the liftgate. i'm using 2"x4" tube with 1/8" steel plate on walls and floor

[irishgoldcleanups]

u can use 2"x4" inside dia. tube with 2"x4" c channel to connect the extension on top make sure it is a sollid three wall connection that u will need an over head hoist to lift.

i am a class b auto & truck mechanic & metal fabricator.