1970 Z28 Flywheel Part Number

1970RSZ28 · #1 03-14-2006, 02:30 AM

Can anyone tell me the correct part number for the flywheel on a 1970 Z28 LT1 motor? Thanks in advance!

**Mr70** · #2 03-14-2006, 02:36 AM

Part #3868802 (1st design) or #3937736 (2nd design).
I've only seen the 2nd design used on the late produced Z/28,but that's just me.

1970RSZ28 · #3 03-14-2006, 02:39 AM

mr70, May I ask where you referenced this number?

**Mr70** · #4 03-14-2006, 02:54 AM

From a manual called Advanced Service Information.
A yearly compilation of Engineering Service letters,TSB's,Tech. Bulletins,Service News & Assembly manual part numbers & revisions.This comes from the 1970 version.

**Jonesy** · #5 03-14-2006, 04:33 AM

Will the part number differ from the casting number on the flywheel??

Jacsey 70Z · #6 03-14-2006, 06:14 AM

My flywheel shows 3978458 N Date B 24 0 never been off the car took the front cover off and and there it was. Not sure what the "N" means (maybe night shift), the car is a 04B Norwood car.

1970RSZ28 · #7 03-14-2006, 07:39 AM

My flywheel shows 3789783. I cant say that it is original to the car. Car was built in L.A.
mr70, Can you find these numbers in any of your publications.

**Jonesy** · #8 03-14-2006, 03:35 PM

The reason why I asked is typically the part number does differ from the casting number on flywheels.

**Mr70** · #9 03-14-2006, 07:06 PM

Those two part #'s I listed earlier are for Auto trans. equipped cars only,so forgive me for not listing the manual ones.(Both transmission types were available on the Z/28 begining in 1970)
I would use an actual owner of one of these cars,equipped w/the trans. type like yours for a better reference,like Jack Seymour especially.

That is true about these part #'s not being the exact same that's listed on the flywheel itself.I have not seen to many of these in person,but noticed just now in the parts books that some mention a completely different number will be cast into the flywheel itself.There were many part# changes for these Flywheels within the years after 1970.
I have only taken notice of the later #7736 in person with it's two staggerd bolt hole mounting pattern.
I can not find either of the two Flywheel numbers Jack & Ray relayed listed in any of my materials.
What does the 1970 Camaro Assembly manual say?
I would imagine the Deuces shared it as well?

68SSCamaro · #10 03-15-2006, 03:19 AM

The flywheel in my 68 Camaro is 3973456 cast G 1 2 (1972). I have a 3789733 for it. Both of these are for an 11" clutch. I suspect these are the casting numbers that the others have. I don't know what is correct for 1970 but 3789733 was used at least until 1969. I agree that you need to find out what was on original cars.

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