That new pump looks like it belongs on the 2.5 liter 4banger in an S-10. The larger bolt circle appears to be the same as the later model diameter. I've found pulleys on S-10 pickups that work fine on the 6cyl's but it may take a while for you to locate them. Conversely, all of the pulleys I have on my 292 right now are from late 70's applications, and they had P/S and A/C, which puts the two outer belts quite far out on the crank. That make for grooves on the water pump pretty close to the pump flange, which is what you need.
If you can find a pulley that is the right depth but not the right bolt pattern, leave the flange alone and merely file the pulley holes radially (slot them) until they fit the flange. That way you will have a pulley that can be used on either an early or late water pump without going to any trouble of swapping flanges. I've seen the results of poor workmanship when swapping those flanges, and it ain't pretty when the fan comes off the shaft. There is a lot of forward load from the fan trying to pull itself like an airplane into the radiator.
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David
newbie #4153
