Ok, since your thinking of goodman, I can speak as someone who installs only goodman/amana . Run a new lineset. Atleast use R-11 flush. Anything less voids the warranty on R-410a. Also, Goodman's R-410a units have a tendency to have alot of vibration, which'll probably transfer through the concrete.
Run a new lineset.
"Better tell the sandman to stay away, because we're gonna be workin on this one all night."
"Dude, you need more than 2 wires to a condenser to run a 2 stage heatpump."
"Just get it done son."
Dad adjusted