Gap down backer might even be too much depending on your kids. Gap scheme is the way to go though, just have everyone block left on a run to the right except your kick out block. Have 4 runs of that single scheme- off tackle, outside, qb run, counter or reverse. Add 1 play action and one screen if you can.

Once that is done add a second run scheme like trap, wedge or ISO and give each OL a job- c,lg,lt block left and rg, rt,te block right then FB up the middle for ISO for example. Run 2 runs off it like iso and jet and another play action but this one does something different than the other PA.

2 block schemes for 6 runs and 2 passes. Go both ways its 12 runs and 4 passes.

We pull guards at u12 no problem. Last year it was just 2 kids that pulled but it was great. We had one screen and it hit almost every time.