vacume mod

[Kisner]

I had the same question 4 years ago. When I got our 68, it also had a late model C-4 tranny in it with the same modulator. The previous owner had about a 4-inch tube on the other port going nowhere (open). I was afraid to plug it or remove the tube, since I had no clue what it was for, so I just left it hanging there. Tranny runs great so I haven't messed with it since. But, I would still love to know what it was originally for, or if I should cap it.

[COORS]

the smaller port or the larger port?

[Kisner]

The open tube (about 4 inches long going nowhere) is hooked to the small port of the modulator on mine, while the large port is hooked to about a 4-inch rubber tube which hooks to a steel tube running to the top back of the engine. Where the pipe ends next to the engine, I have another 4-inch rubber tube hooked on that end which hooks to the engine. Like I said, I never knew if any of this was hooked up correctly so I left it alone. The car (and transmission) have run great in the 4 years since it was restored so I left well enough alone.