My 89 s10 blazer is a 4.3 automatic. push the gas and she purs like a kitten but when i slow down (about 2nd or 1st gear) theres a loud clank! It may not be a big deal but its freaky and i dont have any idea how to diagnose it. Anybody know what it could be?

 

Could be your u joints. Lay under the truck and try moving the drive shaft to see if there`s play. My truck makes a clunk noise sometimes also when I slow down and then accelerate again. Found out that gm has some loose tolerances in the drivetrain and would have to live it