New minimum SEER is 13.The new outdoor unit,13SEER ,has a different design then an old 8-10 SEER,it has more refrigerent,for one thing.
An old coil 8-10 SEER will not work ,in most cases ,with the new 13SEER outdoor unit.
However a new coil Designed for 13SEER ,can work with the old 8-10SEER outdoor unit,may need to add a hard start kit to the outdoor unit ,as the indoor could have a TXV .