I’m in the process of replacing the timing chain on my ‘71 C3 350. Since I need to remove the water pump anyway, I figured it’s a good opportunity to replace the old one as well.

After reading a bit on the forum, I found that the C3 small block uses different pulleys and pumps compared to other Chevy SB engines. From what I understand, the issue arises only if you use a Corvette style pump with a non Corvette style water pump pulley. But if I use a “normal” short style pump with the matching pulley, it should work fine?

Also, the crankshaft pulley shouldn't be any different from other SB crankshaft pulleys, or are there any differences?

Thanks in advance for any help!
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If you have a Corvette-only water pump, then the pulleys will bolt up to the replacement.
These are the dimensions:

 

pg0000,

Keep in mind that if you do not use the specific Vette pump, then all of a sudden:

Why doesn't my ALT pulley line up anymore?
Why doesn't the A/C pulley " " " ?????

 

Delete

 

Thanks for all the information. That already helps a lot.

But I am still unsure about the pump/pulley sizes. The engine uses the standard SBC alternator bracket and standard crank pulley. So why would there be an issue with using a standard SBC pump with the standard pulley? It should only be an issue when using the Corvette style pump with a standard pulley or using a standard SBC short pump with a Corvette style pulley?
Or am I missing something?

 

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I assume you already studied post #2.

No expert on using a short W.P. on a Vette but have read enough info that tells me not to do that.

I have also found that the bolt pattern is different for the fan & pulley with the Vette W.P.
I once purchased a chrome WP pulley. Package stated fits all SBC. Nope! Not a Vette.

Some posters have drilled out a std pulleys bolt holes to accommodate.

Also, the position of the fan in relation to the shroud could be a factor.

I have beat around the bush telling you to, stick with specific Vette W.P.

 

pg0000
Here you go. Save this to your bookmarks/favorites. You can search GM part numbers any time.

I have accumulated a bit of pulley info if you have specific questions but this should get you what you need to find out. I would recommend sticking to known pulley numbers that match and mate correctly ...otherwise you'll give yourself a lot of heartache.

You can also check placed like corvette central -----lotsa times they list original gm part numbers for what they are selling. Great for cross-referencing.

http://www.gmpartswiki.com/getpage?pageid=52023

 

Thanks! Sounds like I am going to order the Corvette specific pump and save me all the problems with not doing that.

 

Order not only Vette specific but correct year model too.
Later on, SBC Vettes had the impeller with reverse rotation.

 

Pulleys don't usually just wear out. Is there something wrong with your pulleys?

Look up the part numbers and then look at ebay. New pulley prices are about ridiculous.

 

If you have a belt that was "slipping" on a pulley from your engine they might get a "glossy shine" on the area contacted by the belt. This can lead to terminal squeaking and squealing of the belt. I have take pulleys and cleaned the belt contact area using glass beads in a sand blasting cabinet. Suddenly they noises are gone and the belt gets traction once again.

Choose the pulley used on your particular Corvette "carefully". I ordered a new set of pulleys from Paragon many years ago and they sent me the first revision water pump pulley which was subject to a recall in January of 1968. The recall changed the pulley diameter to make it spin the water pump more quickly which slowed down the overheating problems. The second pulley I got was the correct diameter for after the recall and it worked great. Paragon could have been nice and mentioned that there was a new pulley part number listed for my application, instead they sold me two pulleys and one is useless. Typical Paragon...

I went with a March Performance Serpentine belt system which solved any noises from the original pulley and fan belts. Now I have one size belt that does everything for my engine. The serpentine system is much cleaner than the factory belt drive system. No More Squeaking with a serpentine belt.....

I have found that as long as you are clear about the fact you are looking for a Corvette water pump, you will usually get the right size and shape water pump. I recently pulled a Stuarts Stage 2 water pump off and put in its place a Edlebrock Corvette water pump in that shiny finish they sell it in. It has been fairly easy working with the BB and its parts, so far only Paragon has sold me the wrong parts and they are supposed to specialize in Corvettes...