1969 L71 Flywheel Which is correct??

[Grant W.]

Trying to find out what is correct or correct application. I am not a mechanical guru but an nuts and bolts guy for C2 or C3

I have a 69 L71 and a couple of flywheels and trying to figure out what is correct for the engine,

Correct 621 belhousing

Flywheels as follows

3973456N Dated A13I
168 tooth
Set up for an 11 inch clutch
Which I have a near new Center force set up for it.

3988999 N Dated F106
168 tooth
Holes are drilled for
10.5 inch clutch.
The clutch is used and my mechanic told me to use it as a boat anchor.

If this 3988999 flywheel is not the correct application. What is it used for with 10.5 inch clutch

I appreciate the mechanical guru's to point me in the right direction

Thanks, grant

[Joe L.]

Re: 1969 L71 Flywheel Which is correct??

Trying to find out what is correct or correct application. I am not a mechanical guru but an nuts and bolts guy for C2 or C3

I have a 69 L71 and a couple of flywheels and trying to figure out what is correct for the engine,

Correct 621 belhousing

Flywheels as follows

3973456N Dated A13I
168 tooth
Set up for an 11 inch clutch
Which I have a near new Center force set up for it.

3988999 N Dated F106
168 tooth
Holes are drilled for
10.5 inch clutch.
The clutch is used and my mechanic told me to use it as a boat anchor.

If this 3988999 flywheel is not the correct application. What is it used for with 10.5 inch clutch

I appreciate the mechanical guru's to point me in the right direction

Thanks, grant

Grant------


The GM casting #3973456 flywheel was not used for the 1969 model year but it is SERVICE for most 1969 Corvette applications except L-88 or those L-71 equipped with the MA-6 clutch option. It was released about 1970 for applications requiring a standard weight, 14", neutral-balanced flywheel for 11" clutch applications. This includes most 1969-81 Corvettes except L-88, MA-6, LS-4, LS-5, LS-6, and some 1978-79 with L-48. It also includes 1966-68 big block except L-88. The 3973456 was used in PRODUCTION after about 1969 and will perfectly SERVICE the applications I have mentioned.

The GM casting #3988999 was never used for a Corvette application I know of although it may possibly have been used for some 1978-79 Corvettes with L-48. It is a 14", standard weight, neutral-balanced flywheel for 10-1/2" clutches.

[Grant W.]

Re: 1969 L71 Flywheel Which is correct??

Hi Joe!!!!
Hope all is good for you. Thanks for your help on this mechanical stuff. I will resurface the 3973456 and use the near new Center force clutch. Getting closer in having the 69 L71 done...now it needs frame restoration and a paint job. Its only been 6 years since I got the car.
I will use the 3988999 as a boat anchor when I go trout fishing on the lake.

Thanks again for your help,
grant