A residential rental home I plan to sell to my son for $350K which is $100K below fmv and hold in escrow to buy different rental property for $350K+. Will gain be taxed?

[larsongene]

Assuming I meet the 45 day and 180 day requirement of a 1031 exchange. And file a gift tax return for the $100K gift. Can I shelter all the gain?

[larsongene]

Thank you for this link.  Rental home has been held for many years.  The son, will use the purchased rental home as his primary residence, likely for several year(at least 2).  I intend to purchase another rental property with the proceeds from a 3rd party within the allowed period (Intermediary will hold proceeds until closing on the 1031 exchange).   In the exchange, am I required to purchase the next rental at or more than the sell price($350K) or the fmv ($450K) of the rental home sold to son?