Water pump re installation.

Can anyone solve the mystery of where to put this bolt from a Nissan 1987 4x4 z-24 pickup after replacing water pump. I am putting on a new water pump. It is bolted on and all the holes are filled. I am about to reassemble the parts I took off to get to the waterpump. I took out the radiator, the fan shroud, took off 2 belts and a bracket that was over the water pump. I have a bolt that I cannot figure out where it came from over a month ago when I was working on it and had to stop.


The bolt is a 12MM head M8-1.0 x40 MM threads and it has a lockwasher on it and there is a number 7 on the head. I think it is an original bolt. There was no nut left in my box I was putting the parts I took off in so I think it goes into a threaded hole somewhere. I had to take out the radiator, took off the belly pan, took off the 2 belts. Any help will be greatly appreciated. I went to 2 auto parts stores and they were not any help. Is there an exploded parts diagram somebody has that would help? Is there another place or way to figure this stuff out? I have a chilton repair manual but could not find any help in there. Please help if you can, Thanks