So here is the data I have collected from many 1968 build sheets from the Pontiac plant. A few of the boxes they would put the last 2 or 3 digits of the part # in the box. Like the starter box, 53 stands for 1108353 Ram Air/HO starter, and 55 stands for 1108355 standard GTO starter. In the air cleaner box, 826 stands for 6424826, the STD GTO air cleaner. The SPACER/CLUTCH box next to the FAN box will have a 53 for 535253 std flex fan spacer, or PH for GTO with A/C fan clutch or PG for Lemans with A/C fan clutch. But the FAN box for GTO's I have seen AA code for A/C cars, BB code for non A/C cars. The one RA II car that I have a build sheet for (car #16 on the Ram Air Roll Car) has code 34 in the FAN box. That coincides with a Lemans with no A/C the 34 code with 53 spacer. I'll try to put it into a chart.
FAN CODE --SPACER/CLUTCH---ENGINE--- DESC.
AA-----------------PH--------------------- YS-------- GTO AUTO WITH A/C
BB-----------------53----------------------WT--------68 GTO 4-SPEED NO A/C
AA-----------------PG----------------------YN--------68 LEMANS AUTO WITH A/C
34------------------53----------------------YN--------68 LEMANS AUTO NO A/C
34------------------53----------------------WY-------68 RAM AIR II GTO
So AA and BB do not match up to the fan part#'s, so the AA/BB must just be a code like PH/PG.
The 34 code does not match up to the 4 blade fan (9798940) but it does not match to the 5 blade flex fan either (9791346). Is the 9798940 a new part number for a superseded number? The most convincing evidence I have for the 4 blade fan on the 68 RA cars is the build sheets of the RA II car and the 68 Lemans with no A/C. They both list the 34 code. I will post pictures of those two. If anybody else has any other 68 build sheets that would be helpful too.
