Financial advice on conversion

Yes, we don't give "advice", but i would appreciate suggestions.

I have about $200K in a 403b from a former employer (left alone, but eligible to rollover to an IRA), $200K in a 403b from by current employer, and $55K in a Roth IRA ($44k contribution basis).  I am single, age 58, and already in the 24% bracket.  The thought occurred to me that I could rollover/convert the former employee 403b to my Roth IRA, withdraw the contributions to pay the tax, trading the immediate loss of $50,000 against future payouts that are completely tax-free.

 

Thoughts?