Is this a good rebalancing for my 403B account

I just changed my future allocations for 50% vanguard institutional index Instl Pl And 50% Vanguard developed markets index Ins Pls. My goal is to get the portfolio to around 60% US equities and 40% international . Then do 60/40 from there on out. My goal is to be as close to the three fund portfolio as I can, aside from bond allocation because I Am 24 and want to stay 100% equities at this Time Any advice is greatly appreciated. Thank you!!