Starting Issue w/ 92 Blazer? Help?

Well I am a pretty decent home mechanic and I was asked to diagnose a problem with a 92 Blazer w/ 4.3 Vortec, automatic, 4wd... the lady said she was driving along and the vehicle died. When trying to restart she only heard a loud clunk from the starter. She bought a new starter which I tested before I put it on (it worked fine off the car).. Installed starter with a weak battery, tested battery and showed bad cell so we replaced it as well... Now the vehicle still clunks just once when attempting to crank, on occassion it may turn the engine over one or two revolutions... I have heard about fusible links and other electrical issues but I would like to have input into what or where the places I should check to diagnose the no start...

If I were you, the first thing I would do is pull the spark plugs and see if it will crank then. If it still won't crank, try to turn the engine by hand both forward and backwards a couple revolutions. When the fusible link goes bad, it doesn't get better by it self. They are there for high amp power circuits like headlights.

CPI injector could be leaking badly and hydrolocking a couple of the cylinders.

Suggest removing the upper plenum cover and looking for washing.

Also, you can look down the IMTV valve under the vortec top plate with a flashlight and look for golden washed spots.