c1 water pump identification

[John F.]

I pulled a replacement pump of some sort off of my 327. It has a TC, 3771, and 8 holes for the fan to bolt to. Does anybody know what it is from? I can't make out the part number. It is deteriorated.

[Martin N.]

Re: c1 water pump identification

JOHN-

Sounds like a generic replacement pump. Do you know if this pump has ever be off before? Most original replacements come with just the four holes to fit that specific year, make and model. Although I've heard over the past few years that the GM / DELCO water pump and clutch fan replacements now come with the 8 holes so they can cover a wider variety of applications. Maybe Joe L. will pipe in with the particulars.

Marty

[Joe L.]

Re: c1 water pump identification

JOHN-

Sounds like a generic replacement pump. Do you know if this pump has ever be off before? Most original replacements come with just the four holes to fit that specific year, make and model. Although I've heard over the past few years that the GM / DELCO water pump and clutch fan replacements now come with the 8 holes so they can cover a wider variety of applications. Maybe Joe L. will pipe in with the particulars.

Marty

Marty and John-----


Yes, this one does sound like an aftermarket-type casting. With a photo we might be able to confirm that.

Most original waterpumps used in PRODUCTION (i.e. actually installed on engines at the factory) had hubs with only 4 drilled and tapped holes. Most NEW GM SERVICE waterpumps as well as most rebuilt waterpumps have "8 hole" hubs. The aforementioned is not a "hard-and-fast" rule, but a GENERAL rule.

[John F.]

Re: c1 water pump identification

Thanks guys. I just ordered a rebuilt correct 609 fro Bill Mock. Need to bite the bullet to get as close to numbers matching as I can. Gosh this is fun. I'll be able to pull a water pump with my eyes closed!

[Martin N.]

Re: c1 water pump identification

JOHN-

Could you post some pictures of the pump you pulled?

Marty

[John F.]

Re: c1 water pump identification

Here are pics.

[Mike E.]

Re: c1 water pump identification

You'll find that the 609 has a correct smaller threaded opening at the top for the bypass fitting than the one you have pictured. Your present one needs a reducer sleeve to make the bypass fitting fit.

[Joe L.]

Re: c1 water pump identification

Here are pics.

John-----


This is an aftermarket pump. The casting is non-GM, although its configuration is very similar to the GM #3859326. It was likely cast by a foundry which uses the foundry mark "TC" and built into a finished waterpump by Bosch, GMB, or many others.