The Chevrolet/GMC "486" is an aluminum 168 Tooth Bellhousing.
 It has a 5 1/8" center hole to accommodate the General Motors Truck transmission,
 and has room enough for a factory 12" clutch and pressure plate.



Front view
This picture shows the typical bottom section of the truck
aluminum bells and the distinctive starter "bump" of a 168 tooth
flywheel clutch cover. 



Part #
Part number 460486 is on opposite side from clutch fork hole.
This example has the number cast upside down as compared to most bells.




Top view
Looks like a "621" from this angle. This example
has no GM logo on the upper ribbed portion.




Fork side view
Fork hole is x .
The "486" Chevrolet/GMC bellhousing was cast
to only be used on left hand drive cars.

  


Z-Bar stud boss
The z bar stud boss is a blind tapped hole on this bell.
If your application needs the engine side stud to be mounted
in the bell this should be checked before purchasing if
you don't want to do it yourself.




Bottom view
Many sellers will try to hide this view and call this a 168 tooth
bellhousing (which it is) to try and get more money than they are
worth. You should be able to pick one of these covers up at a swap
meet or salvage yard for under $100. Just plan on spending hours cleaning it.




Inside view
The 460486 bell uses a bigger inspection plate with a
different bolt pattern than the car plates.
The inspection plate is attached using  (4) 1/4"- 20
cap-screws (bolts)



Inside view
This bell uses four 1/2"-12 threaded holes for trans mounting
with the same pattern as GM Muncie,T-10, Saginaw car transmissions
and has only one clutch fork hole and stud location.




The "486"has a  relieved and squared off area for
12" factory clutch and pressure plate assembly.