Hi, I'm rebuilding the same 38's right now. Just got a nice rebuild kit from Eblag. Here. The carbs I have found have a crappy Dynojet kit st.1 and I going to replace the tube's and needles with originals. There is not enough info to tell what size jets you should use, but I would start small because of the lack of oxigene in your area. When I was riding a 1216 with large intake valves, the mains were #165 if my memory serves me well... But that works in a country below sea level and a temperature around 60F
A DJ 3135 kit would fit if you want to go from original.
Keep me informed, good luck.