The maximum timelock allowed in Bitcoin is 0xffff, about 455 days. So you can't make a timelock of 120 years.
OP_CLTV is different from OP_CSV (absolute vs relative). It allows for the locking of Bitcoin to be evaluated either by unix time or block height, the latter for which is up to >9000 years while the former is until 2106.
You are right, forgot about the absolute timelock value.