Excellent news.
For about five years I worked in an area where trucks were popular. The C/K trucks with 4.3 and manual tranmissions always seemed to "hang" when shifting gears. I've never checked to see if the issue was the IAC / throttle follower, spark, or another value. It soulds like you're on the track to solving it.
I recently located a file which has all of the calibrations which were on the old gmecm website. I'm in the process of organizing them now. If I locate any interesting and relevant files I'll add them.
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