Author Topic: Harmonic Balancer GM part number....  (Read 2453 times)

Camaroon

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Harmonic Balancer GM part number....
« on: February 09, 2012, 11:16:54 PM »
Greetings.   Wondering if anyone knows the correct GM part number for the correct harmonic balancer for a
1969 350 cu in 300 horse engine?
 
I was given the part number of 6272222 as correct for this application, but not sure. Any help would be appreciated!

A link to, or listing of, harmonic balancers for 1st gen Camaros would be great!

Thanks in advance.

tmodel66

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Re: Harmonic Balancer GM part number....
« Reply #1 on: February 09, 2012, 11:34:19 PM »
When I was doing research on my L48 your number was superseded by 3947704. I looked in Jerry's book but it's not listed. That's the only thing I wish Jerry would have done in his book was pay a little more attention to the L48.
Daniel  
'69 SS 350/4 speed  Fathom Green--POP

bertfam

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Re: Harmonic Balancer GM part number....
« Reply #2 on: February 10, 2012, 12:44:45 AM »
Group 0.659
1969 All w/4BC (350) - Balancer Assy - 3947704

Ed

Camaroon

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Re: Harmonic Balancer GM part number....
« Reply #3 on: February 10, 2012, 02:46:05 AM »
Thank you gentlemen. I assume this is a 8 inch diameter balancer? I also assume the original (old) GM part number was 3947704, and the new (current)  GM part number is 6272222 ? Also, any good sources to purchase the correct timing chain cover (and it's GM part number) would be great.

I also enjoy Jerry's book, and agree that more attention to the L48 and more color pictures and closeups would be fantastic. Perhaps in his 5th Edition?  ;)

bertfam

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Re: Harmonic Balancer GM part number....
« Reply #4 on: February 10, 2012, 02:53:03 AM »
Not sure about new numbers, but this EBAY AUCTION says it's NOT compatable with the 69 Camaro.

As for the timing cover:

Group 0.206
1969 ALL W/4BBL carb (302, 350) - Cover Assy - 3946870

Ed

1968 Z28

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Re: Harmonic Balancer GM part number....
« Reply #5 on: February 10, 2012, 03:43:53 AM »
My 1983 P & A catalog states that the #6272222 fits 69-70  All w/4BC (exc H/Per, spc H/Per).  So it should work OK.
Jerry G.

Z28-1968-07C-Norwood
Ermine White, Red Std. Interior
2nd. Owner, 38,000 miles

Camaroon

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Re: Harmonic Balancer GM part number....
« Reply #6 on: February 10, 2012, 05:11:06 PM »
OK, thanks again guys.
Ed, I really appreciate the detail you provide, including the group numbers.
As a side question, what is the basis for the different sized harmonic balancers ? i.e an 8 inch dia balancer for the L48 four barrel engine and and a 6 3/4 inch dia balancer for the 2 barrel version?    I assume there is a difference between the rotating assemblies, and thus a different sized (mass) balancer is required. Perhaps it's the crankshaft used that determines the balancer required ?
Also, not to be overly abusive with asking for help, but GM part numbers for '69 L48 for the following would be very much appreciated:
Alternator upper bracket
Alternator lower bracket
Alternator spacer with tab
Clip for holding Negative battery cable onto the upper alternator bracket
Thank you very much for your assistance.     

bertfam

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Re: Harmonic Balancer GM part number....
« Reply #7 on: February 10, 2012, 05:43:00 PM »
John can answer your "why" question better then I can, but you got the jist. The material characteristics of the crank determine the balancer. Cast cranks need a different amount of dampening than forged cranks so different balancers were used.

As for the part numbers, the L48 used the same alternator mounting brackets as the base V8 engine, so all the numbers are in the AIM on UPC 6, sheet A5.

The clip is on UPC 12, sheet A9, number 5 (3857706).

Ed

Camaroon

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Re: Harmonic Balancer GM part number....
« Reply #8 on: February 10, 2012, 06:38:29 PM »
OK, Ed, sounds resonable. So, I'm guessing the 4 bbl L48 has a forged crank, and the two barrel L65 has a cast crank?
So just for fun, assuming the balancers can be interchanged between L48 and L65 (assuming these have same crank end dimensions) what symptom would result if the incorrect balancer were installed? Some odd vibration at certain RPM's?
Regarding the alternator brackets, here's the GM part numbers I think are correct per a GM parts counter guy:
Alternator upper bracket   3951500
Alternator lower bracket    3951574
Alternator spacer with tab   3825451
If you can cross check these numbers with your info, I will toast you with a "Here's to Ed" while lifting a cold one this evening!
Thank you!
.

bertfam

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Re: Harmonic Balancer GM part number....
« Reply #9 on: February 11, 2012, 03:06:34 AM »
No, per the AIM the upper (#3) is 3932410, the lower (#7) is 3951500 and the spacer (#8) is 3951574.

Ed

Camaroon

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Re: Harmonic Balancer GM part number....
« Reply #10 on: February 11, 2012, 05:21:57 PM »
Thanks again, Ed, I appreciate it. Here's to you, and , an early congrats to you, as you are about to hit the 1500 posts count. Quite an accomplishment !
  :-*