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Top Sellers

Chevy 153 Tooth Inspection Plate (New OEM)
Chevy 153 Tooth Inspection Plate (New OEM)
$21.00
Bellhousing Shield Bolts (R)
Bellhousing Shield Bolts (R)
$3.95
(R) 3993851 Clutch Fork Boot
(R) 3993851 Clutch Fork Boot
$9.75
#3729000 Ball Stud (New OEM)
#3729000 Ball Stud (New OEM)
$8.75
(New OEM) 14007355 Fork Boot
(New OEM) 14007355 Fork Boot
$14.33

New Releases

(NOS) GM #9795915 Shift Cable Bracket
(NOS) GM #9795915 Shift Cable Bracket
$25.00
55 Chevy Clutch Fork Push Rod Kit (OEM)
55 Chevy Clutch Fork Push Rod Kit (OEM)
$80.00
5/16
5/16" x 9/16" Dowel Pin
$1.25
  1. Home
  2. GM PARTS SEARCH
  3. Clutch Housings
  4. Chevy Engine
  5. Casting #3788421 63 Vette & Pass. 153 Tooth

Casting #3788421 63 Vette & Pass. 153 Tooth

The "421" Chevy bellhousing is a 153 tooth

aluminum bell with a small 4-1/8" transmission

hole and no z-bar mount provision. This bell is

essentially the same as a 3840383 bell with a

small transmission retainer hole. The "421" is a

one year only (1963) bellhousing that was made

to fit the 4 speed transmission on Corvettes and

Full sized Chevrolets of that model year.

In order to fit any other 4 speeds to this bell the

center retaining hole would need to be enlarged to

he more common 4-5/8" diameter or the transmission

front bearing retainer would need machined to fit.

Since the 3840383 and sister 3858403are plentiful

and cheap, I would avoid the 3788421 unless it is

appropriate to your application.

Front View
Front View

In the picture above this bell looks like any other

Chevy 153 tooth bell. But if you look closely you

can see that the pivot ball stud location appears to

be farther away from the center hole. This is just

an illusion. The stud location is the same as on other

General Motors Housings.

The trans is mated using four 1/2"-12 threaded holes.


Part #, Engineering code, Date code
Part #, Engineering code, Date code

The passenger side clutch fork knock out is were

you will find the part number and any engineering

change codes. I've read that the Four dotes in the

circle on right pertain to a date code,but will take

more research to substantiate.

(How does December fit into the half circle?)


Top View
Top View

My example has "GM" cast into the upper portion.


Fork Side
Fork Side

This example doesn't have a provision for a Z Bar

mount stud.


Bottom View
Bottom view

 Once again this view looks the same as the "383"

and "403" bell housings


Side View
Side View

Passenger side view shows almost straight bell to

engine mounting flange typical of 153 tooth fly-

wheel clutch housings.

The 1938-1965 Chevrolet parts Catalog lists

this flywheel housing as part number 3788419

with the note (Ident. No. 3788421)


Inside View
Inside View

This bell utilizes a one piece inspection cover that

is attached with four 1/4"-20 bolts.


Inside Close Up
Inside Close-up view

In the above view you can see that in order to open

up the center hole 1/2' (to make it compatible with

common GM 4 speeds), the reinforcement around

the hole would be virtually eliminated.



3788419

0.683 HOUSING, Flywheel and Clutch

Applications per the 1938-1965 Chevrolet parts catalog effective date October 1, 1964
63 PASS., CORVETTE (exc.409, police).....(Ident. No. 3788421)

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 won’t be sorry).
This is a fun and interesting part of the hobby!



Parts For Sale [12]

(OEM) 3788421 63 Chevy Bellhousing
(OEM) 3788421 63 Chevy Bellhousing
Sold
$120.00
Chevy 153 Tooth Inspection Plate (New OEM)
Chevy 153 Tooth Inspection Plate (New OEM)
Sold Out
$21.00
(New OEM) 14007355 Fork Boot
(New OEM) 14007355 Fork Boot
Sold Out
$14.33
(R) 3993851 Clutch Fork Boot
(R) 3993851 Clutch Fork Boot
In Stock
$9.75
Add To Cart
(R) 14007355 Fork Boot
(R) 14007355 Fork Boot
Sold Out
$8.00
#3729000 Ball Stud (New OEM)
#3729000 Ball Stud (New OEM)
Sold Out
$8.75
(New OEM) GM 5/8
(New OEM) GM 5/8" Block Dowel Pins
Sold Out
$8.80
Bellhousing Shield Bolts (R)
Bellhousing Shield Bolts (R)
In Stock
$3.95
Add To Cart
Bellhousing to Engine Bolts
Bellhousing to Engine Bolts "A" Head (R)
Sold Out
$10.50
Bellhousing to Engine Bolts
Bellhousing to Engine Bolts "M" Head (R)
Sold Out
$7.95
Adjustable Fork Ball Stud
Adjustable Fork Ball Stud
Sold Out
$23.98
Transmission to Bellhousing Bolts
Transmission to Bellhousing Bolts
Sold Out
$4.99
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