I presently have a 12 year old heat pump Rheem 2 1/2 ton compressor outside with Rheem 3 ton air handler inside. When running it had insufficient capacity. The existing lineset is 3/4 and 3/8. It has been recommended that I replace the outside unit with a 3 1/2 ton R22 Amana SEER 13 unit using the existing lineset and later upgrade the inside unit when necessary. Will this work ?