Water pump bolts

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Picture of my old bolt.

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WTF , that lower bolt looks like it could be 5/16 , I hope for you sake it is , that would be an easy fix , good luck.
 
Just for reference.

Moparts Tech Archive
Small Block
Small Block bolt sizes

oil pan
5/16"{18}x 3/4" amount needed 18
valve covers
1/4"{20}x3/4" amount needed 10

fuel pump
3/8"{16}x1 1/2" amount needed 2

thermostat housing
3/8"{16}x1" amount needed 2

intake manilofld
3/8"{16}x1 1/2" amount needed 12

water pump & timming cover as a combo-set
3/8"{16}x5" amount needed 4
3/8"{16}x3 3/4" amount needed 3
3/8"{16}x1" amount needed 3
3/8"{16}x2" amount needed 1

distibuter hold down
5/16{18}x 3/4" amount needed 1

Don't forget the washers to go with the bolts.
 
Thanks for all the input peeps!

Working the next few weekends so will have to remain as it is for now

Let you know what I find and decide to do in the end
 
Note that your water pump and the one pictured in post #36. are different. Post #36 is a pre '70 cast iron pump, yours is a post '70 and up aluminum pump. The inlets from the radiator are on opposite sides.
 
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EACH of those bolts is location specific.
If you stick a too long bolt into the DRIVER'S side,
it is possible to drive it right into the cylinder and crack it,
And then you are in big trouble.

The coat-hanger in the hole will tell you where the cylinder is, and so, DO NOT install a bolt that long!

I respectfully suggest you take that timing cover off, and clean those tunnels out, and chase the threads in the block. Then you will likely notice that the gasket is shot, or perhaps the cover is rotted.In either case coolant could get into the oilpan, yours wouldn't be the first one to have this happen. And you might also find that the timing chain is ready for replacement.

With the cover off, and laying on a flat surface,
you can mock it up and determine exactly which bolt goes where.

Some guys are afraid to take the timing cover off, because it is tricky to reinstall. but IMO, your first time having sex was way trickier. Well, OK, my first time was,lol.
 
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Dusterguy thanks for posting the ad from parts mix.
The list from Moparts just did not seem right.
 
The red paint had me fouled up. I thought I was looking at a early 273 or 318 like mine with cast iron water pump.
 
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