'56 Bellhousing & Flywheel Info Needed

[Brooks G.]

My '56 came off the line on August 14, 1956. I am not sure if I need a bellhousing with casting number 3704922 which I have or 3733365 which I don't. The judging guide I have says that 3704922 was used thru mid-1956. What is considered mid-1956? I am also wondering about the flywheel. Did the Corvette use a different flywheel than the passenger cars of that year? I thought I read somewhere that the Corvette used a larger diameter pressure plate and disc than the non-power pack passenger cars of that year. Thanks in advance!

[Joe L.]

Re: '56 Bellhousing & Flywheel Info Needed

My '56 came off the line on August 14, 1956. I am not sure if I need a bellhousing with casting number 3704922 which I have or 3733365 which I don't. The judging guide I have says that 3704922 was used thru mid-1956. What is considered mid-1956? I am also wondering about the flywheel. Did the Corvette use a different flywheel than the passenger cars of that year? I thought I read somewhere that the Corvette used a larger diameter pressure plate and disc than the non-power pack passenger cars of that year. Thanks in advance!

Brooks-----

I feel pretty confident that your car would have been built well within the period of use of the GM #3733365 bellhosuing.

As far as the 1956 model year was concerned, the flywheel, pressure plate assembly and friction disc used for Corvette were essentially unique to Corvette. The flywheel was a 14" unit and the clutch was a 10-1/2" unit. Some 1956 Corvettes MAY have used a 10" clutch.

After 1956, some of the Corvette pieces were used for passenger car applications.

[Gary C.]

Re: '56 Bellhousing & Flywheel Info Needed

Brooks, 365 bellhousing would be correct for your car. There are many 365 bellhousings available. Make sure you get one with the throwout arm pivot that screws in from the transmission side with 3/8 inch allen socket wrench and has about a 7/8 inch screw thread on it. Ones you don't want have a stud that screws in from the inside of the bellhousing. Also single year date. Gary....

[Brooks G.]

Re: '56 Bellhousing & Flywheel Info Needed

Joe and Gary, thanks for the reply. I guess I will look to find the right 365 bellhousing. As for the clutch assembly, I will probably try to use what the '57 thru '62's use. I will have to see if it will bolt up to the flywheel I already have. If not, hello "Driveline".

[Tom P.]

Re: '56 Bellhousing & Flywheel Info Needed

Brooks,
EXCEPT for some trucks (which used an 11in clutch), ALL 55-62 cars, including Vettes, ONLY USED the large, 14in diameter, 168 teeth flywheel---------------------THAT'S THE ONLY THING MADE, AND THE ONLY THING THAT FIT IN THE BELL HOUSINGS OF THOSE YEARS!
Also, those flywheels had a bolt pattern for the 10in clutch (later replaced by 10.4in clutches).
As I already mentioned, SOME of the larger truck flywheels of those days had a bolt pattern for the larger 11in clutch.
Once the bell housing, clutch, front cover, pan and tranny is assembled/installed, the casting number cannot be seen (IT'S COVERED UP BY THE FRONT OF THE TRANNY!). The flywheel can't be seen (to tell if it has a 10in or 11in clutch). BUT, the casting date on the bell housing CAN be seen.
Even though it is not correct, I prefer to have a later (70s) flywheel which has the bolt pattern for the larger, 11in clutch.

[Brooks G.]

Re: '56 Bellhousing & Flywheel Info Needed

Tom, thanks for the info. From the way it looks I will be able to use the flywheel that I already have as it was from a 265 engine back in the day. Back then(1967) my 265 engine blew and I replaced it with a 283 short block and used all of the 265 parts I could which included bellhousing and flywheel. Back then I was a kid on a tight budget. I wish I still had that engine block. I had to trade it in on the 283 short block. All of you already know about "hind sight".

[Joe L.]

Re: '56 Bellhousing & Flywheel Info Needed

Brooks,
EXCEPT for some trucks (which used an 11in clutch), ALL 55-62 cars, including Vettes, ONLY USED the large, 14in diameter, 168 teeth flywheel---------------------THAT'S THE ONLY THING MADE, AND THE ONLY THING THAT FIT IN THE BELL HOUSINGS OF THOSE YEARS!
Also, those flywheels had a bolt pattern for the 10in clutch (later replaced by 10.4in clutches).
As I already mentioned, SOME of the larger truck flywheels of those days had a bolt pattern for the larger 11in clutch.
Once the bell housing, clutch, front cover, pan and tranny is assembled/installed, the casting number cannot be seen (IT'S COVERED UP BY THE FRONT OF THE TRANNY!). The flywheel can't be seen (to tell if it has a 10in or 11in clutch). BUT, the casting date on the bell housing CAN be seen.
Even though it is not correct, I prefer to have a later (70s) flywheel which has the bolt pattern for the larger, 11in clutch.

Tom----


I think that 55-56 were different than later in many respects as to clutch related parts.

For one thing, 1955 used a different flywheel than 56-62. It was definitely a 14", 168 tooth piece. It was GM PART #3714462 and it was not used for Corvettes after 1955. 1956 Corvettes used flywheel GM PART #3729003 which was, of course, thereafter used through 1962.

1956 used a different pressure plate and friction disc than 1957 and later. The 1956 pressure plate and cover assembly was GM #3729002. The friction disc was GM #3727585. Neither of these parts was used for Corvettes after 1956. GM describes both as being "10-1/2 inch".

1957 Corvettes used pressure plate and cover assembly GM #3744752 and friction disc GM #3740642. GM describes these as being "10 inch".

All 57-62 did use a 10 inch clutch, though.