Agreed but, if pistons and rings are from different suppliers, go with the ring suppliers recommendation as the rings make contact with the bores not the pistons.
"The oil rings are usually pre-fit, as long as you order them for your bore size. Gap the compression rings at 0.016-0.018 for a 4.00 bore, 0.018-0.020 for a 4.030 bore. Go about 2-4 thousandths bigger if you plan on running boost or nitrous."