<VV> Bell housings

[Clark Hartzel]

The part number for bell housings is not as simple as it seems.
Any number cast onto an item (cylinder heads, blocks, bell housings) is the
part number for the casting, not necessarily the machined part.
A bell housing with a cast number 625**** is definitely an early and the
late is 3832176.  There is a gray area somewhere around 1963-64 when Chevy
started using the late casting for early machined parts.  Those are
supposedly daubed with blue paint over the part number indicating an early
part.  If the housing has been dipped or blasted the blue paint is gone and
you can't tell.
Here is a way to tell what you have:  Measure the distance from the engine
mounting face to the seal flange surface.  The early is .64 and the late is
.58  This difference has to do with the late longer stroke crank and stepped
face flywheel.
You can use an early bell housing on a late but you need an .06 thick spacer
under the flange on the seal.  I have heard that a head gasket will work as
a spacer but I am not sure of that.
Clark Hartzel, former CPF Curator and keeper of the drawings.