* Block: Multiple freeze plugs are located within the engine block itself. These are typically found on the sides of the block, and sometimes on the bottom, near the oil pan. They are usually cylindrical and recessed.
* Water Pump: There is usually at least one freeze plug located on the back of the water pump housing where the water pump mates to the engine block.
To be completely sure, you will need:
1. A Repair Manual: A shop manual specific to your 1998 GMC 350 5.7L engine is the best resource. These manuals will have diagrams clearly showing the location of all freeze plugs. You can find these online or at auto parts stores.
2. Visual Inspection: Once you have a general idea from the manual, carefully examine your engine block and water pump. Remember to be cautious around hot surfaces if the engine is still warm.
Caution: Don't confuse freeze plugs with other similar-looking parts. Refer to your repair manual for accurate identification. Replacing a freeze plug incorrectly can lead to serious engine damage.
