are you making 263 just overtop your mortgage, tax ins? the general rule is you take your rent and divide it in half and that's the operating cost...taxes, insurance, maintenance, management insurance but not your mortage. so 1k month rent, 500 to operating cost, 400 to mortage=100 is your cash flow.
the basics of a 1031 are you sell the property and purchase a new more expensive property. so sell a 500k place you need to buy a 501k or more new place. You must identify the new property within 6 months and if you defer the taxes down the line.