My bronco has always lived near sea level and since I brought it to Denver it has run really rich. Today I pulled the jets to see what size they are so I can order new ones. I found that it had 2 different jets in it, a 48f and a 49f.

Is it supposed to have 2 different sizes or were they messed with at some point? I would think that they should be the same. Also does anyone have a suggestion as to how many sizes down I should go? I was thinking about going down to a 46.

Thanks in advance

No they shouldn't have different sizes in them. You probably want about 12% smaller (leaner) jet size for this altitude. If I remember right it's 3% for every 1500 ft change in elevation. You might be able to Google what the jet internal diameters are and find something 12% smaller. If you are going to use it more at altitudes above Denver's then you might consider going a little smaller. You just have to watch how much highway driving at lower altitudes so it doesn't run too lean. Since I drive mostly in the mountains I run a little leaner on my Edelbrock.