Hi, I have a 97 Sambar carb’d, no AC. I live at 7000 feet elevation and am thinking I may need to re jet the carb. Truck runs very smoothly but has no power in 5th. Max speed is about 50 mph floored and gets worse with wet cold weather. At lower elevation I was able to get up to 65 mph no problem with plenty of throttle left. I’ve searched for part numbers for jets with no luck. Any ideas on a solution?