Engine Mechanical problem
1993 Dodge Shadow 6 cyl Front Wheel Drive Manual

after replacing the water pump on the mitsubishi v6, i have 3 identical 8mm bolts left over. they are 42mm
long on the shaft, half of which is thread and the most
distinguishing feature is that they all have both a flat
washer and a lock washer on them. manual transmission,
air conditioning. the car is back together, running, not leaking oil or coolant and not rattling with anything loose.
where might these bolts have come from?