First time at the strip!

Change one thing at a time. Start with the rear. The 3:55's would be great for your combo. You'll probably pick up .8-1.0 seconds, even at that elevation. You can't upgrade your cam until you change the gears anyway. If you up the cam now it will be slower. You should have 1.6 rockers on the magnums so that's already helping a little in the upper rpm range. If you go to a new carb go with the 770 avenger. I'll bet the jetting will be real close out of the box. Leave the worn out front shocks on the front. Put in a cheap shift kit and go out and test&tune it after each change.