When chaging the hight and logicle hight in a custom world file for the neather to 256 from 128 all ores, caves, basalt in basalt deltas, gravle, blackstone, and nynillium cut of at 128 and nether trees stop genorating after about 150.

(edit): I know ores are sopost to stop but I dont think caves are sopost be cut flat at 120