#3779553
General Motors Casting # 3779553 Clutch Housing
The "553" Clutch housing is listed
in Chevrolet parts catalogs as part number
3785644. This is one of the earliest aluminum
Chevrolet Bellhousings, and although it is also
listed as a replacement for 230 cubic inch engine
in taxis it was probably born from the early years
of NASCAR and Super Stock drag racing.

Light Weight Aluminum
The weight savings with the introduction of this
aluminum piece over the cast iron clutch housings
previously available was huge. This bell is drilled
and tapped for the 13/16" ballstud used on High
Performance engines on earlier models and almost
exclusively from this 1963 on.

Inside view
It is hard to tell the difference this bellhousing
from it's cast iron brothers, until you pick it up.
I think when they were putting together the first
"lightweights" to compete with Pontiac this part
was a piece of the puzzle.

Close up
The "553" uses the Chevy car 4 speed transmission
bolt pattern (T-10, Muncie, Saginaw) that uses four
1/2"-13 threaded holes and the 4 11/16" center hole.

Starter Mount
There are two 3/8"-16 taped and one clearance
hole for the starter to be mounted to the cover.

Fork Hole
The Clutch release fork slot is huge at approximately
5 1/2" x 2 1/2". This bellhousing uses the GM Part
# 3781385 rubber clutch fork boot.

Bottom View
This clutch housing has the open bottom design
typical of the pre-1963 styles. The inspection
plate is two piece stamped steel.

Starter Hump
This housing has a "bumped out" starter pocket
typical of 168 tooth flywheel housings.

Top Hole
The example I have has the top hole drilled out
making it compatible with 6 cylinder engines. I
don't know if there was a version with this hole
left undrilled as with other bells.

Drivers Side View
This shot shows the huge clutch fork hole, the ball
stud hole and the z-bar bracket mounting holes.

Bracket Mounting
There are two 3/8"-16 tapped holes for attaching
the Z Bar bracket on some models (Corvette).

Identification Number
As mentioned earlier the parts catalogs sometimes
used the part # 3785644 with the notation that
the identification number is 3779553. This casting
also has a 5 over three dots.
The "553" Clutch housing is listed
in Chevrolet parts catalogs as part number
3785644. This is one of the earliest aluminum
Chevrolet Bellhousings, and although it is also
listed as a replacement for 230 cubic inch engine
in taxis it was probably born from the early years
of NASCAR and Super Stock drag racing.
Light Weight Aluminum
The weight savings with the introduction of this
aluminum piece over the cast iron clutch housings
previously available was huge. This bell is drilled
and tapped for the 13/16" ballstud used on High
Performance engines on earlier models and almost
exclusively from this 1963 on.
Inside view
It is hard to tell the difference this bellhousing
from it's cast iron brothers, until you pick it up.
I think when they were putting together the first
"lightweights" to compete with Pontiac this part
was a piece of the puzzle.
Close up
The "553" uses the Chevy car 4 speed transmission
bolt pattern (T-10, Muncie, Saginaw) that uses four
1/2"-13 threaded holes and the 4 11/16" center hole.
Starter Mount
There are two 3/8"-16 taped and one clearance
hole for the starter to be mounted to the cover.
Fork Hole
The Clutch release fork slot is huge at approximately
5 1/2" x 2 1/2". This bellhousing uses the GM Part
# 3781385 rubber clutch fork boot.
Bottom View
This clutch housing has the open bottom design
typical of the pre-1963 styles. The inspection
plate is two piece stamped steel.
Starter Hump
This housing has a "bumped out" starter pocket
typical of 168 tooth flywheel housings.
Top Hole
The example I have has the top hole drilled out
making it compatible with 6 cylinder engines. I
don't know if there was a version with this hole
left undrilled as with other bells.
Drivers Side View
This shot shows the huge clutch fork hole, the ball
stud hole and the z-bar bracket mounting holes.
Bracket Mounting
There are two 3/8"-16 tapped holes for attaching
the Z Bar bracket on some models (Corvette).
Identification Number
As mentioned earlier the parts catalogs sometimes
used the part # 3785644 with the notation that
the identification number is 3779553. This casting
also has a 5 over three dots.
Quick Facts
Center Hole : 4 11/16" (4/58")
Fork Hole Approximately : 5 1/2" x 2 1/2"
Ball Stud : 13/16"-16
Transmission : Most GM car (Muncie, Saginaw, Borge Warner T-10/ST-10
Engine : Chevrolet (1st and 2nd generation Small Block and Mark IV Big Block)
Motor Mounts : No
Z Bar Mount : Yes
Starter Mount : Yes
Applications found in Chevrolet Parts Catalogs
3785644 (Ident. No. 3779553)
0.683 HOUSING, Housing Assembly, clutch (aluminum)
60-63 Corvette (Chevy Parts Books) (Chevy Parts Books)
60-61 Pass. w/H/Per., SP. H/Per. (348) (Chevy Parts Books)
61-63 Pass.(409) (Chevy Parts Books)
62 Pass. w/H/Per.(327) (Chevy Parts Books)
64 Taxi (230) (2nd design) (Chevy Parts Books)
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 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!
0.683 HOUSING, Housing Assembly, clutch (aluminum)
60-63 Corvette (Chevy Parts Books) (Chevy Parts Books)
60-61 Pass. w/H/Per., SP. H/Per. (348) (Chevy Parts Books)
61-63 Pass.(409) (Chevy Parts Books)
62 Pass. w/H/Per.(327) (Chevy Parts Books)
64 Taxi (230) (2nd design) (Chevy Parts Books)
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 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!