I find in my Lang that smaller, like 12" long, splits work much better.
You don't have to push the ends into the center either.
Long splits seem to sometimes give you too big a fire for what temp you want to maintain. This is also true in my POS offset as well.
IMBAS Certified MOINK baller
Shirley 30x70 awesome smoker
POS Offset that still puts out some mighty fine Q
55 gal drum in the building stage
Part of "THE BLACKSTONE POSSE"