Flywheel for a '56

[Pierre J.]

I intend to install flywheel #3703870 in my '56 along with a 10" clutch. This is a 14" wheel that came out of a '57 full size chev. One of the local car builder told me that I may have problem fitting the original starter. Myself, I don't see the problem but would just like to make sure. Has anyone gone through a similar experience?

Thanks for the help.

Pierre G. Joly #34410

[Mike M.]

Re: Flywheel for a '56

Pierre: i messed up and posted the response in the previous post. mike

[Joe L.]

Re: Flywheel for a '56

Pierre----

I THINK that this flywheel will work for you, but I can't say so, for certain. Here's the deal:

1956 Corvettes originally used flywheel GM #3929003 (casting #3729004). As a matter of fact, 1956 Corvettes were the very first Chevrolet car to use this flywheel which later became the standard flywheel for most C1 Corvettes as well as many other Chevrolet passenger cars.

The GM #3703868 flywheel (casting #3703870) was originally used for some 1955 Corvettes with V-8 and 1955-56 Chevrolet passenger cars with V-8. I can't find any reference to the fact that it was ever originally used for a 1957 Chevrolet. According to GM, 1957 Chevrolet passenger cars originally used the GM #3729003 (casting 3729004) flywheel. However, I wouldn't rule out the possibility that some 1957 Chevrolet passenger cars, especially early builds, used the 3703868 (casting 3703870).

However, the GM #3729003 (casting GM #3729004) flywheel replaced, for SERVICE, the GM #3703868 flywheel (casting 3703870) on August 1, 1957 when the latter unit was discontinued.

So, we KNOW that there is REARWARD compatibility of the 3729003 with the 3703868. What we don't know, for sure, is if there is FORWARD compatibility of the 3703868 with the 3729003. I'm about 99% sure that there is, though. By the way, if the 3703868 flywheel was originally installed in the 1957 Chevrolet that you obtained it from, that pretty much confirms the FORWARD compatibility and full interchangeability of the 3703868 with the 3729003.

[roy braatz]

Re: Flywheel for a '56

Should work OK But you can put the wheel on the engine then starter, then turn the starter over while checking it.

[Bernard M.]

Re: Flywheel for a '56

I recently disassembled my 56 clutch. It was using an 11" clutchplate and a flywheel with the casting number 3714463 (or 83). I'm not sure of it's original application. This flywheel, which I just had resurfaced today, has an 11 clutch mating surface and is 14-1/8" in overall diameter. It was housed in a standard 1956 3704922 bell housing and used a 1956 1107627 starter with 1119789 solenoid. This combination was working fine and will most likely go back together the same way.

[Bernard M.]

Addendum

My flywheel was dated L187 so I suspect it to be 1958 issue.

[Joe L.]

Re: Flywheel for a '56

Bernard-----

GM flywheel casting #3714663 (aka GM PART #3714462) was used on 1955-58 passenger cars with HD clutch and/or overdrive. It was also used on some light trucks and commercial vehicles. It MAY also have been used on some 1955 Corvettes with V-8.

This flywheel is designed for use with an 11" clutch. However, it MAY be dual-drilled for both 10" and 11" clutches. I'd be interested in learning if your has an extra set of drilled and tapped holes for the 10" clutch.

[Bernard M.]

Re: Flywheel for a '56

Joe, Thanks for the information. This flywheel is not drilled for a smaller pressure plate. It has a 5/8" outer surface ring which the pressure plate mounting holes are centered in. Concentric inside that is a 3/8" wear indicating ring (lower cast surface), inside which is the clutch plate mating surface which measures 11" across.

[Joe L.]

Re: Flywheel for a '56

Bernard----

Thanks, that's very useful information. It means that IF this flywheel ever was actually used on any 1955 Corvettes, then those cars also received an 11" clutch.