Whilst the minimum volume that can be used in the drums is likely to be pretty small (the large JOBO print drums I use for 5x7 film require a minimum volume of 100 ml), the general recommendation with D-76 would be to use 250 ml of undiluted developer for each 80 square inches of film (i.e. per roll of 135/120/sheet of 8x10). Larger volumes than this will probably give more consistent results.
So for the 11.5x23 cm sheets (about 40 sqin), you could get away with 125 ml stock D-76 per sheet (it will give more consistent results if you can use more than this per sheet, say 200 ml).
For the 18x58 cm (about 160 sqin), you would need 500 ml stock D-76.
And for the 18x31 cm (about 84 sqin), I would suggest using a minimum of 300 ml stock D-76.