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§ The Cross Ram Manifold Top Plate identified on the cover page and the subject of this document is consistent with production Chevrolet Cross Ram components. It presents in excellent used condition.

§ A most interesting and distinctive anomaly appears on the top portion of the manifold lid as follows:

The Casting Date that normally appears on the underside of the top plate is cast into the outer, top surface, directly under the casting part number.

The earliest production manifold top plates (those appearing with PN# 3941130) did not have casting dates (see photos below). They are most often found paired with O-Dash numbered (Prototype) lower manifold halves produced after 12/15/67 and were among the units pushed to “insiders” through Engineering.

Shown above is the underside of a Top Plate that was part of the first production group produced with PN# 3941130 on the top. Note the absence of a casting date on the underside. The first batch of production Top Plates had no casting dates on the top or bottom. They were produced prior to 9/26/68.

Shown above is a production Cross Ram top plate (cast PN# 3941130 on top) showing the normal position of the cast date on the underside behind the forward carburetor. The above is dated 9-30-68.

The vacuum holes are a give away that these are production pieces.

The omission of dates on these early pieces was due to an oversight that was corrected on or about 10/26/68 (the date the subject top plate was produced). The correction (the addition of a cast date) was made in order to be compliant with the standard quality assurance process that tracks defect occurrences of runs based on production dates.

There where two molds used to produce the Cross Ram. One for the top plate and one for the lower half and only one component part from each could be made at a time.

The standard procedure was to run a pilot piece prior to each run. Then evaluate for form, fit and function and either continue the run and/or adjust accordingly.

At the point the date omission was to be corrected, the operator placed the date impression on the outer portion of the top plate in the same position it appeared on the prototype originally. Regardless whether it was accidental or intentional, the date location was changed after inspection to the underside of the manifold where it was is not outwardly visible once the manifold was assembled. The date position for the upper half was then consistent with the location of the date on the lower half.


Rick’s Top Plate above showing the atypical Casting Date 9.26.68 (See Insert) placed under the Winters “Snowflake” and Chevrolet Part Number	Regular Production Top plate illustrates the typical appearance of the production manifold top having only the Winters “Snowflake” and the Chevrolet Part Number

Under side of Rick’s production Top Plate illustrating the absence of a Casting Date in this location	Production Top Plate above illustrates the Casting Date 9.30.68 (See Insert) in the typical position on the underside.

Often times when a defect or anomaly (in this case a casting date on the outside) does not affect form, fit or function, it is passed and packaged. This practice is especially true for the low volume production parts where there is a high demand, as was the case with the Cross Ram components at that time.

The number 7 inspection stamp (see image below) seen on the Manifold top plate above both the part number and the casting date indicates that the piece was pulled, inspected and conditionally approved for packaging. This type of inspection was typical with pilot parts, and random samples based on quality control standards calculated from risk analysis. The stamp location implies that these two areas were under scrutiny.

It was not unusual for an evaluation or pilot piece to be pressed into service due to the high demand and short supply of these components. Often times Chevrolet Engineering and Product Performance would send out what they had on hand to racers/combines who were considered “insiders”. The aforementioned is consistent with the subject Top Plate since the only way for a pilot piece to leave Engineering would have been if it were to be used on an insider’s race chassis. The apparent competition use of this component agrees with that statement.

This research attempt concludes with the successful and comprehensive documentation of a significant race bred Chevrolet development.

· In addition, the anomaly adds to the character, speaks to the production process and in large part is historically significant in that it adds to the history of the development of the Chevrolet Cross Ram Manifold.