Deep Pulley Question for you '67 L78 Owners

[jeffschevelle]

Originally Posted by Chevelle SS 396 L78

I've attached a pic of my '67 Chevelle L78 engine when practically new (you can tell the firewall is nice and fresh!). Note the alternator.....this appears to be a standard pulley arrangement. Either some L78's came out of the KC plant with non deep pulley alternators, or someone on the engine assembly line in Tonawanda screwed up!

The alternator was not assembled or installed at the Tonawanda engine plant. It was installed at the car assembly plant. As to when the pulley got put on it, see below.

Originally Posted by plumL78

Jon Mello had a 67 Z survivor with around 11k miles that had a standard alt pulley on it with a heavy duty alt. He thinks they didnt have a heavy duty alt. with a deep groove pulley at the time the car was built so they just used what they had. Do you recall your orig chevelle having a heavy duty alt. option ?

In 67 (and prior) the Alt pulley and fan were installed at the car assembly plant, not at the Delco alternator assembly plant. That's why there are no $1500 alternators for 67 and prior, like there are for later years where the alt part number depends in part on what pulley and fan it was assembled with (which makes the entire alternator rare and valuable if it came with a pulley and fan for a rare engine option). In 67, a 37 amp alternator is just a 37 amp alternator, part number 1100693.

So in 67, like any other sub-component assembled in the car assembly plant, standard 37 amp alternators, or any optional HD alternator, would have been assembled as a "job" for that particular car, with the fan and pulley combo specified for that car's engine (and other options that might affect the pulley). So there should not have been a situation where they were "out" of HD alts with a DG pulley. The pulley would have gotten installed for THAT job, and put onto a "pulley-less" HD alternator from inventory.

However, it is certainly possible (for John's Chevelle or for Jon's Z28) that (A) the plant was out of DG pulleys that day and used the specified back-up part, or (B) two alts got mixed up and the wrong alternator got put on that car (so the alt with a DG pulley got stuck on a 283 or something), or (C) the guy on the alternator subassembly line just messed up and put the wrong pulley on the alt for that job.

But none of those situations would make the non-DG pulley "right" for any OTHER L78 or Z28, unless there is solid proof that THAT car came with the "wrong" pulley.