Confirming 1965 L79 with AC Alternator Pulley size

[Fred Y.]

Just wanted to confirm----I've seen this mentioned many times here. My 5th edition JM is saying that my 1965 350 HP with AC only should have a 3 3/8" pulley diameter on the alternator. Ive seen paragon claim that BOTH the L79 & L76 both used the 3 5/8"

My rebuilder put on a 2 15/16th pulley & my alternator is bottoming out on the adjustment bar so I KNOW there's an issue.

So here we now have 3 different sizes & since I am bottoming out on my adjuster bar there's something wrong with this picture.

I'd appreciate your take on this guys.

Thank you,
Fred

[Ray K.]

Re: Confirming 1965 L79 with AC Alternator Pulley size

Fred,

Looking at my 1965 6th Edition JM the following is listed:

L79 - 350 HP - with C60 AC - 3" diameter - Part #3848023

L79 - 350 HP - with C60 AC & N40 PS - 3" diameter - Part #3848023

L79 - 350 HP - with N40 PS - 3 5/8" diameter - Part #3829387

Ray

[John F.]

Re: Confirming 1965 L79 with AC Alternator Pulley size

My 64 with the L76 has a 3 5/8" if that helps you in any way.

[Leif A.]

Re: Confirming 1965 L79 with AC Alternator Pulley size

Fred,

Looking at my 1965 6th Edition JM the following is listed:

L79 - 350 HP - with C60 AC - 3" diameter - Part #3848023

L79 - 350 HP - with C60 AC & N40 PS - 3" diameter - Part #3848023

L79 - 350 HP - with N40 PS - 3 5/8" diameter - Part #3829387

Ray

Fred,
You stated in your original post that you measured your current alternator pulley at 2 15/16"...close enough to the 3" Ray has shown in post #2. Quite possibly the installed belt is too long if it's bottoming out on the adjustment bar. Measure the belt and buy one an inch shorter and see if that doesn't solve the problem. Also, if you can, check the part number of the belt that's currently on there.

[Fred Y.]

Re: Confirming 1965 L79 with AC Alternator Pulley size

Son of a gun. Thanks men. My 5th edition says 3-3/8" ---Guess I'll need to grab a 6th edition. Yes Leif I'm going to check the belt as well, but I just received it last wk from Quanta. I think I need to dig a bit deeper into this & confirm I have a 680 water pump pulley as well.