Deep Pulley Question for you '67 L78 Owners

[plumL78]

They all had a deep groove pulley with #3844100AK on them except for the calif. smog cars. I believe some of them have been found to have a double groove alt pulley. they also could have been a 42 amp alt. when heavy duty battery was ordered

[Steve Shauger]

Here's some component #'s on my car.

[Chevelle SS 396 L78]

Thanks for the info so far guys! 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!

I had problems with my power steering belt going off under hard acceleration [i.e. drag racing! :-)], and I've often wondered if the power steering pump also didn't have a deep pulley. This will always be a mystery to me. The crank pulley no doubt was the 3 groove deep pulley arrangement (the car had no smog & no A/C of course).

I thought I'd ask this question on this forum, since there were probably more L78 Camaros in '67 than Chevelles. Just looking for answers.

I am building an L78 engine to as close as my original engine's specs as I can get.

Thanks for the input,

John

[1967 4K]

Far fewer 67 L78 Chevelles than Camaros. I think the Chevelle # is in the 600’s, not certain.

[jeffschevelle]

Another interesting tidbit shown in John's early picture is the bypass hose clamp. It is a tower clamp rather than the usual flat style clamp. Assuming those clamps were not changed before the picture was taken (which John's post indicates would not be the case), this tells us his engine was built at Tonawanda somewhere between 5/1/67 and approximately 6/14/67 !

Per a Chevrolet service bulletin dated 5/22/67, 396 and 427 engines built on or after 5/1/67 through “approximately” 6/14/67 used a “new clamp” to prevent the bypass hose from blowing off. Up to that time, the nipples in the intake and water pump had no lips on the ends of them, which (per the bulletin) was occasionally resulting in hoses coming off. Then on “approximately” 6/14/67 a new nipple with a lip on the end went into use at Tonawanda, which allowed them to go back to the original flat style clamp.

The bulletin does not identify the type or the part number of the temporary clamp used at Tonawanda, but it does say that in service repairs if a hose comes off the dealer should use an AC hose worm clamp, part number 3840818 (which is the stainless AC worm clamp with a locator tab sticking out one side). So I had always assumed that Tonawanda also used an AC hose worm clamp on the engines assembly line between 5/1 and 6/14.

But John's picture suggests that they used a tower clamp instead during that period. So now the four NOS AC hose clamps that I had squirrelled away for my two cars with T0509EG engines will have to be put back with my AC parts stash!