Coming into 400-650k profit. Where to invest?

[Jordan A.]

Selling a property this month.

Currently renting for 8k, mortgage is $4500. 
Profit of about $3500 monthly but selling due to market and some personal issues.
profit will be 400-650k pre tax (if I do 1031 exchange). 

trying to figure out where to put these funds to maximize cash flow or flipping x2 profits in a short time.

any local so cal people looking for investors on new construction, flips or multi unit?