93 gmc sierra truck with 305 , it as been 5 alternator that i have install they last either 3 day to one day it been a puzzel if anyone can help me it be appriciated

I would be checking somewhere else.
Battery, cables, grounds, accessory loads.
The alt is designed to keep the battery charged and to run the accessories.
It is not designed to charge a dead or partially dead battery. If the alt is running at full output for extended periods of time, this could cause it to fail.

I woudl def check the grounds and any other cables, i had the same issue with my 94 and i changed out my battery and it solved hte problem but then a month later the alt went but all and all the problem was solved without much money spent.

I was working at an auto parts store and had someone with the same problem, turned out to be the connector on the side had a short in it.