With no other codes, it may be hard to diagnose.
Check color of fire from the coil, should be bright blue, about half inch jump r more, ,if it's orange or sorta-blue with orange balls in the spark, the module or coils is suspect.
Check the ohms of the spark plug wire. per GM the spec on wires is 12-15k Ohms per ft, with a maximum of 35k ohms on a long wire.
Rust inside the dist cap where the coil wire connects can cause similar issues, happened to me.
Also on these 4.3 engines, the distributor busing wears out and causes contact between the stator and pick up coil, it should make a small noise just before quitting.
Here''s a TSB on your unit
Bulletin No: 876507A
Summary Description: ROUGH IDLE AFTER START, WHEN VEHICLE HAS SAT OVERNIGHT AND POPPETS STICKING
Get a can of Chemtool B-12 and pour the whole can in mixed with a couple gallons of gas. Warm engine fully and run highway speeds, open throttle and rev the engine a bit to clean injectors.
The link to the TSB's is not just for GMC/Chevy, you MUST check both to see all of them, odd huh..
Also, check this forum if you have not found joy with any of the previous data. www.s10forum.com/forum/index.php