I am installing a Moen shower spout. The spout has iPS threads. The brass nipple has to be exactly 6 3/4" long. Since the nipple threads are NPT on both ends cutting either or both ends to achieve the correct length will not work because of the taper. If I could find a nipple with NPT on one end and IPS on the other, I could cut the IPS side so that it would be the proper length, but I cannot find a brass nipple that has NPT on one end and IPS on the other. How do I solve my problem ? I have brass nipples in lengths of 6 1/2", 7 ", and 7 1/2", but they all have NPT threads. Help please. Thanks.