The f165 is a replacement for a 76p. Probably because turbonetics is able to source them cheap over seas. Precision used these also up until they came out with their new wheels not too long ago. On paper it should flow more. They are copies of the Garrett GT design. Just some slight tweaking so that they aren't exact copies. Pics won't help here. I'd need a 4 bolt housing that was contoured for a smaller wheel previously. Like a t350 or one of the later Garrett GT wheels but smaller than a 65mm exducer. You could order a new one from Precision. They should have it in stock.