I have fished the Rio
Grande more than a half-dozen times, last in 2009, and am going back in Feb. 2011. Early on, we used 7 wt & 8 wt single-hand rods with Teeny 200 & 300 sink-tip lines, with short level leaders and weighted nymphs and leeches, as well as floating lines with longer tapered leaders and dry flies and skaters. Last time there I fished exclusively a 13' 3" 7/8 wt 2-hander with a 500 gr. Skagit head and 15' of t-14 with a short level leader of 3-5" of Maxima Ultagreen 15 lb., alternating between TDF nymphs and big, dark, Intruder-type flies. This combination was very successful. The longer rod and spey casting made water coverage and line management much easier, and the casting was more fun. One of the guys I know who keeps coming back there insists on sticking with SH rods. He's a good fisherman and catches a lot of big fish. How you rig your system really depends on the conditions you encounter at the time. I hear last year the river was high, fast and dirty most of the season, so heavy tips were the order of the day. I understand right now it's high, but clear and dropping. Rain and snow melt in the meantime will determine conditions in Feb. For all we know it could be low and clear, as it has been in other Februarys. Sounds to me that what you have done in the Falklands would work.