Challenger

I just re-jetted my 32/36 in my 85 2wd pickup. I live at sea level but drive up to 4000'. I've never done this before and can't find very much info on how to really do it. Before I started the re-jet the truck ran best with the mix screw out 2 1/2 to 2 3/4. here are the stock settings.

pri idle- 60
sec idle- 50
main jets- 130/150

Now it idles fine at a little past 2 turn out with these changes. but since i've done this I can't turn the idle screw past 1 turn without the engine running really rough.

pri idle- 65
sec idle- 55
main jets- 145/150

I'm I on the right track, or am I just messing things up?

Challenger

I also can't get it to stop backfiring when it's coasting in gear. And I've lost most of my power in the higher rpm range. It used to pull hills in 4th going 65 now I have it floored hitting 55.