And to be honest, unless you are done with earning for life (which I assume you are not), you will be “DCA-ing” one way or another, whether you lump sum this amount or not. 
Perhaps compare the amount to your yearly savings, that might give you another perspective on the significance of worrying about this decision.
If you will have another 60k saved in a year, then why bother DCA-ing these 60k.
I setup a mini-approach in my IPS with windfalls depending on their proportion to total portfolio (e.g. less than 10% - lump sum it in, otherwise break it into pieces and go stepwise), and act accordingly.
Because I simply “feel” better not dumping in significant money at once; even though it might be “irrational”.