Ron, do you have carter yf or rochester, if you have carter I might be interested in buying it,,, I am not so sure that the carb is your problem,,,I may be nuts but I have never had a carb backfire as you describe, seems like mine have always been electrical but I am no expert, by moving the dist and making it run better may seem to support that it may not be the carb.. good luck and let us know, I know how you feel, it is nerve racking to try and fix somthing and not be able to do it and have to take it to a mech,, I know just enough about these old trucks to be dangerous,,, take care........Fred

Redryder pix
My Hotrod
A veteran - whether active duty, retired, national guard, or reserve - is someone who, at one point in his or her life, wrote a blank check made payable to The 'United States of America', for an amount of "up to and including my life."
I am fighting cancer and I am winning the fight | Pain is part of life; misery is an option.