I'm participating in a review of the 1967 JG Table M-13 (K19 spacers) and Table M-18 (small block pulley configurations). We know that there are some errors in the current Table M-18, so there is an effort underway to fix them.
The configurations where there is the most uncertainty are the four configurations when the L79 had K19. Since so few 1967 Corvettes were configured with K19, and many owners removed the K19 parts anyway, there is not much to go on when trying to figure out each configuration.
I've studied the AIM and my GM parts book to get some useful clues, but there are gaps and contradictions. To gain further insight, I have physically mocked up the various configurations using a block on an engine stand. This has turned out to be an important sanity check for testing the various interpretations of the AIM and parts books.
Following are some questions I'm hoping to get some help with:
1) All sources indicate that the L79 with K19 used three different spacer thicknesses between the K19 pump flange and the pump pulley. However, I am not 100% certain that the thicknesses shown in Table M-13 (.339", .497", and .607") are correct. I'm also not sure whether the three part numbers shown in Table M-13 (3890427, 3890423, and 3890425) are correctly matched to the associated thickness. So, any insights here would be much appreciated.
2) I've never seen a photo of any of these original spacers, but I think one end has a raised ridge to index with the 3890421 pump pulley. I'd appreciate any photos of original spacers.
3) For the specific combination of L79 with K19 but no A/C, the belt that drives the A.I.R. pump was in either the second (outer) groove of the 3770245 water pump pulley, or in a third water pump groove created by an add-on pulley (3765427). Either configuration can work, but using the add-on water pump pulley requires an unusually thick spacer. I'm trying to determine what GM actually did for this configuration.
Any helpful input would be greatly appreciated.
The configurations where there is the most uncertainty are the four configurations when the L79 had K19. Since so few 1967 Corvettes were configured with K19, and many owners removed the K19 parts anyway, there is not much to go on when trying to figure out each configuration.
I've studied the AIM and my GM parts book to get some useful clues, but there are gaps and contradictions. To gain further insight, I have physically mocked up the various configurations using a block on an engine stand. This has turned out to be an important sanity check for testing the various interpretations of the AIM and parts books.
Following are some questions I'm hoping to get some help with:
1) All sources indicate that the L79 with K19 used three different spacer thicknesses between the K19 pump flange and the pump pulley. However, I am not 100% certain that the thicknesses shown in Table M-13 (.339", .497", and .607") are correct. I'm also not sure whether the three part numbers shown in Table M-13 (3890427, 3890423, and 3890425) are correctly matched to the associated thickness. So, any insights here would be much appreciated.
2) I've never seen a photo of any of these original spacers, but I think one end has a raised ridge to index with the 3890421 pump pulley. I'd appreciate any photos of original spacers.
3) For the specific combination of L79 with K19 but no A/C, the belt that drives the A.I.R. pump was in either the second (outer) groove of the 3770245 water pump pulley, or in a third water pump groove created by an add-on pulley (3765427). Either configuration can work, but using the add-on water pump pulley requires an unusually thick spacer. I'm trying to determine what GM actually did for this configuration.
Any helpful input would be greatly appreciated.