The problem here is the OP needs the 5 percent yield this fund generates (4.92 percent per Yahoo) for income. None of the replacement suggestions come anywhere near that yield. However, what the OP apparently does not understand is this fund achieves the high yield by investing in below investment grade (junk) bonds. From the fund profile:
Debt securities include all varieties of fixed, floating and variable rate instruments, including secured and unsecured bonds, bonds convertible into common stock, senior floating rate and term loans, mortgage-backed securities and other asset-backed securities, debentures, and shorter term instruments. It may invest up to 100% of its total assets in debt securities that are rated below investment grade.
This is a high risk fund and the yield may not be sustainable. Some or all of that $1,400 a month in income could easily disappear. The OP would do well to investigate alternatives to this fund, as the debt instruments it owns could lose a substantial amount of value or even go to zero if the economy weakens or interest rates rise significantly. Relying on this fund for retirement is not reasonable and the fact that it comprises 60 percent of his 401k is extremely risky. In the OP's shoes, I would re-evaluate my options.
In addition, this fund is held in a 401k. The OP should understand his distribution options if the money stays in the 401k, and whether it makes more sense to roll the account over to an IRA when he retires.
ETA: The current yield on Wellesley is 2.88 percent. That's representative of a lower risk balanced fund with a tilt towards income.