Phil, you'll have to measure the torsion bars to determine what size they are. It needs to be an accurate measurement using either a 0-1" outside micrometer or a good vernier caliper and the number you're looking for is somewhere between .810-.920" measured at the bars smallest outside diameter lets say about a foot from the end. Measure both bars to be certain someone didn't screw up before you and I'd recommend the .890" bars with the 440.
Terry