The Chevrolet and GMC part number 3704923 is
the lower cover or pan of the two piece clutch
bell housing cover.
Reproduction Car SetThe Part # 3704923 is the cover at the top in
picture above. The "923" fits both early car and
truck bellhousings.
OutsideThis is the outside of a new GM part. The paint is
shinier than the aftermarket part.
InsideIn this view you can see the drain hole at the bottom
and get a sense of the depth needed to inclose the
flywheel and clutch assembly.
Part #3704923The example I have has the part number sticker
the inside.
On "553" In this picture I have a reproduction pan mounted
on a part # 3779533 aluminum bellhousing. This
is a "true" inspection plate as it can be removed
by loosening four (4) bolts and removing one (1).
I have personally tried this cover on the following bellhousings.
3704922
3779553
3925505
I will try this cover on others as soon as I recover from my hernia operation.
Clutch cover
applications should be used as a guide to the type of bellhousing used
originally used on a vehicle.
Covers should be bought to fit the
bellhousing you have. 37049230.679 UNDERPAN, Clutch Housing Cover
Applications per the 1976-81 Buick parts catalog effective date July, 1987No listing
Applications per the 1976-81 Chevrolet parts catalog effective date July, 1986No listing
Applications per the 1976-81 Oldsmobile parts catalog effective date July, 1987No listing
Applications per the thru 1975 Chevrolet parts catalog effective date April, 1983
Applications per the Thru 1975 Oldsmobile parts catalog effective date April, 1982No listing
Applications per the 1953-1982 Corvette parts catalog effective November, 1981
Applications per the Thru 1975 Pontiac parts catalog effective date October, 1977
Applications per the thru 1965-1972 Buick parts catalog
Applications per the 1962-1970 Chevrolet parts catalog effective date October 1, 1970
Applications per the 1938-1965 Chevrolet parts catalog effective date October 1, 1964
Applications per the 1973-1978 GM Light Trucks parts book effective February, 1985
Disclaimer: Factory correct applications are your responsibility. GM made part and part # changes with no rhyme but a reason (no production interruptions at any cost).
Application charts and part numbers are for replacement parts that were available at the time of parts book printing.My observations come from the parts I have in my collection or other reliable sources your parts may differ.
If Factory correctness is your goal, do more research, join car clubs,
forums and buy an assembly manual if one is available for your Project Car (you wont be sorry).
This is a fun and interesting part of the hobby!
