C1 & C2 Corvettes General C1 Corvette & C2 Corvette Discussion, Technical Info, Performance Upgrades, Project Builds, Restorations

Waterpump Decoding Help

Thread Tools
 
Search this Thread
 
Old Jul 22, 2020 | 02:26 PM
  #1  
kvette89's Avatar
kvette89
Thread Starter
Melting Slicks
20 Year Member
Active Streak: 30 Days
Active Streak: 60 Days
Photogenic
 
Joined: Oct 2004
Posts: 2,744
Likes: 31
From: "southern" Illinois
Default Waterpump Decoding Help

Looking for some assistance in identifying this waterpump. It is a 3782608 without casting date and has a large "GM 6" on it. I'm guessing this is a late 63 through October 1964, prior to the beginning of date code in November of 64. What I'm really not sure of is the application of "GM 6" waterpumps.

Thank you very much for any assistance you may offer.



Reply
Old Jul 22, 2020 | 03:29 PM
  #2  
Panama 58's Avatar
Panama 58
Melting Slicks
25 Year Member
Active Streak: 30 Days
Community Favorite
Top Answer: 1
 
Joined: May 2001
Posts: 3,355
Likes: 766
From: Mint Hill North Carolina
2024 C2 of the Year Finalist - Unmodified
2023 C2 of the Year Finalist - Unmodified
2022 C2 of the Year Finalist - Unmodified
Default

Kvette, if I recall correctly, the GM 6 has nothing to do with a manufacturing date. These were sand casted and the 6 represents the sixth casting in a cycle. BTW- I owned a '64 with assembly of mid June and it did not have a date on the 608 water pump. When I replaced it (to be sure it didn't go out on me unexpectedly) I spoke with the guy that rebuilds many of these including most of Bill Mock's that he sells and he felt based on his long history of doing these that the dates were not on '64's. He literally has hundreds of them, so he can see which ones have dates and which ones do not. I am sure there will be some exception to this comment, but he has been at it for over 40 years and is very credible.
Reply
Old Jul 22, 2020 | 05:23 PM
  #3  
JohnZ's Avatar
JohnZ
Team Owner
Supporting Lifetime Gold
20 Year Member
Veteran: Army
 
Joined: Oct 2000
Posts: 38,897
Likes: 1,927
From: Washington Michigan
Default

Originally Posted by kvette89
Looking for some assistance in identifying this waterpump. It is a 3782608 without casting date and has a large "GM 6" on it. I'm guessing this is a late 63 through October 1964, prior to the beginning of date code in November of 64. What I'm really not sure of is the application of "GM 6" waterpumps.

Thank you very much for any assistance you may offer.


The "GM6" is a mold number. For higher-volume castings, they had multiple molds, each with a number for traceability purposes at the foundry. If a problem was discovered during machining of the pump at the engine plant, that number would take them right to the mold that was creating the problem at the foundry.
Reply
Old Jul 22, 2020 | 05:53 PM
  #4  
Panama 58's Avatar
Panama 58
Melting Slicks
25 Year Member
Active Streak: 30 Days
Community Favorite
Top Answer: 1
 
Joined: May 2001
Posts: 3,355
Likes: 766
From: Mint Hill North Carolina
2024 C2 of the Year Finalist - Unmodified
2023 C2 of the Year Finalist - Unmodified
2022 C2 of the Year Finalist - Unmodified
Default

Originally Posted by JohnZ
The "GM6" is a mold number. For higher-volume castings, they had multiple molds, each with a number for traceability purposes at the foundry. If a problem was discovered during machining of the pump at the engine plant, that number would take them right to the mold that was creating the problem at the foundry.
Thanks for the further clarification John.
Reply

Get notified of new replies

To Waterpump Decoding Help





All times are GMT -4. The time now is 08:47 AM.

story-0
2027 Chevrolet Silverado 1500 First Look: Everything You NEED to Know!

Slideshow: Is the 2027 Chevrolet Silverado 1500 the best Silverado yet?

By Michael S. Palmer | 2026-06-16 08:01:12


VIEW MORE
story-1
5 Best & 5 Worst Corvette Daily Drivers

Slideshow: 5 best and 5 worst Corvette daily drivers

By Joe Kucinski | 2026-06-15 10:32:13


VIEW MORE
story-2
The Headlights of Every Corvette Generation Explained

Slideshow: The headlights of every Corvette generation explained

By Joe Kucinski | 2026-06-15 10:17:14


VIEW MORE
story-3
5 Best & 5 Most Overrated Corvette Track Packages of All Time!

Slideshow: The 5 best and 5 most overrated Corvette track packages ever.

By Joe Kucinski | 2026-06-09 12:46:45


VIEW MORE
story-4
Every 2027 Corvette Engine Explained

Slideshow: Every 2027 Corvette engine explained

By Joe Kucinski | 2026-06-09 12:16:31


VIEW MORE
story-5
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette

Slideshow: A Jaguar designer's personal project imagines what a modern front-engined Corvette might look like if Chevrolet revisited the golden age of the Stingray.

By Verdad Gallardo | 2026-06-08 19:53:43


VIEW MORE
story-6
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-7
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-8
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-9
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE