Flywheel

**72-SS-L48** · #1 03-19-2008, 04:10 AM

Can someone tell me what this flywheel decodes to and what it is dated?

Thanks,

-Dave

http://cgi.ebay.com/ebaymotors/ws/eBayIS...AAQ:MOTORS:1123

**John Brown** · #2 03-19-2008, 04:45 AM

11" OEM High Performance GM Flywheet Casting # 3973456 N. GM part# 3973456. Nogular Iron, Weight 28.4 LBS. Dated January 6, 1955?, 1965?, 1975? .

**72-SS-L48** · #3 03-19-2008, 04:50 AM

[ QUOTE ]
11" OEM High Performance GM Flywheet Casting # 3973456 N. GM part# 3973456. Nogular Iron, Weight 28.4 LBS. Dated January 6, 1955?, 1965?, 1975? .

[/ QUOTE ]

Thanks very much John. Can I ask, what book or data base did you use to decode that flywheel?

-Dave

**Mr70** · #4 03-19-2008, 05:08 AM

It looks like a January,6th,1975 date to me,used on all internally balanced Small Block & Big Blocks.
How many teeth are on it..168?..If so that was superceded by Flywheel #3991469 later on & to be used on ALL 1967-85 internal balanced engines w/11" clutch & 2pc. rear seal.

**72-SS-L48** · #5 03-19-2008, 05:14 AM

Yes its 168 Tooth.

nuch_ss396 · #6 03-19-2008, 05:43 AM

The part number: 3973456 tells you that it probably had to
be from a design, or modification sometime in the 1969
model year.

Nuch

**John Brown** · #7 03-19-2008, 06:56 AM

[ QUOTE ]

Thanks very much John. Can I ask, what book or data base did you use to decode that flywheel?
-Dave

[/ QUOTE ]

To tell the truth, even though I do have the dealer catalogues to look it up, I just typed into Google~

3973456 flywheel

~and came up with this.

http://forums.corvetteforum.com/show....php?t=1857077

I must be getting smarter, or maybe just lazy.

Next time I'll do a spell check when I copy information or something from someone else though.

**72-SS-L48** · #8 03-19-2008, 05:38 PM

Wow. I never thought to Google something like that.
Thanks again,

-Dave

Dedicated to the Promotion and Preservation of American Muscle Cars, Dealer built Supercars and COPO cars.