Casting #3788383 62-63 Chevy II 153 Tooth
General Motors Casting Number 3788383 Clutch Housing
This "383" is an aluminum 153 tooth bellhousing
with 4 1/8"center hole, and the example shown
has no z-bar provisions.
The clutch fork hole is at the 7o'clock position,
and the fork stud is lowered to be inline with the
center hole.
Transmission Mounting
The transmission mounting threaded holes (1/2"-13)
are in the GM cooperate pattern and spacing. Here
you can also see the space between the 4 1/8: center
hole and the clutch fork pivot. This separation is
obviously smaller on the casting #3849309 housing.
Bottom View
This casting could have been used on left or right
hand drive cars. The fork ball stud could be threaded
on each side, and the clutch fork knock out is on each
side. This example is for left hand drive cars. The
casting number is probably different for the left hand
drive version.
Right Side
This view shows the straight starter side common
with the 153 tooth flywheel bellhousings.
Top View
GM is cast into this example.
Left Side
The clutch release fork opening can be seen at
approximately the 7 O'clock position.
Casting Number
The casting number is cast into the unused fork
hole knock out.
Engineering codes
The engineering codes are cast on top of the right
side fork hole on this example.
Inside View
Close Up Inside
The above view of the inside shows the straight
line from center hole thru fork stud to the fork hole.
Also shown: how close the lower drivers side
transmission mounting hole is to the fork hole.
This makes the fork boot unique, because it needs
to be notched to clear the mounting bolt.
NOTE:
There is some discussion on forums about opening
up the center hole to accommodate 4 5/8" transmission
bearing retainer. As you can see machining 1/2"
from the center hole will leave no transmission seat
and greatly weaken this bellhousing.
Applications
Disclaimer:
Most parts that I describe and picture, have identification on or with them, others I can identify from other sources and deduction (educated guess).
Factory correct applications are your responsibility. GM made part and part # changes with no rhyme but a reason (no production interruptions at any cost).
Applications are for replacement parts that were available at the time of parts book printing, and when possible model specific assembly manuals.
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!
