Here's what the CRG has on the subject;
<BLOCKQUOTE>quote:</font><HR>Q: [18-Dec-2002] Update: What SS hood ornament was used where and when?
A: At model introduction in September, 1966, the SS Camaro used a special SS hood that included chromed trim that mimicked
the appearance of finned oil coolers. At this time the only SS was the SS-350 model, and the badges on the car read "SS-350".
When the SS-396 was introduced in January 1967, the badges were changed for all SS models to read "SS". The SS-396 could
be distinguished from the SS-350 by the engine emblems. In addition, there is a blacked-out tailpan on SS-396 cars (except
black-painted cars and special models like the 1969 Pace cars). Both 350 and 396 models in 1967 used the finned hood emblem
for the entire model year.
For the 1968 model year, the chromed hood trim for SS396 changed from the simulated finned cooler to a set of simulated
carburetor velocity stacks. The early 1968 model year SS350 continued to receive the 1967-style finned hood trim, but the SS350
trim transitioned to the velocity stack trim as the year progressed. The simulated velocity stack continued for the 1969 model
year with all SS cars using this same hood trim. Related to this, the part number for the 1968-99 hood is different than 1967, with
the only noticable difference being the drains used with the velocity stack trim.
A march built car is 7 months into the production so I don't think that would be considered early producton...