1967 300hp Alternator Belt

[Craig S.]

Here are my part numbers that are stamped into the pulleys:
crank pulley 3755820
water pump pulley 3905995cf
alt pulley 3909815

According to the manual the belt for this application is 3847710 (53.25 inches)





Thanks for your help
Craig

[Wayne M.]

Re: 1967 300hp Alternator Belt

Craig

Although I don't have a '67 AIM, I checked the parts catalogs, and agree with your belt and pulley numbers. Do you have the correct lower alternator bracket that bolts to the front of the LH exhaust manifold and to one of the water pump bolts ? Have you tried removing the alternator pulley, placing the belt in the groove, then seeing if you can reinstall the pulley on the shaft of the alt ?

[Peter L.]

Re: 1967 300hp Alternator Belt

Craig - The parts you list agree with the 67 AIM. Since the water pump and crank pulleys are the correct ones I'd look to see what might have been changed with the alternator brackets to accommodate the AC unit. Have you determined that you have the original "correct" alternator mounting brackets and exhaust manifolds for the base engine? Pete

[Craig S.]

Re: 1967 300hp Alternator Belt

Hi, Thanks for your replys. I do have the correct exhaust manifolds and the atlernator brackets. Does anyone have a 300hp w/no options that can confirm their pulleys and belt?

Thanks for your help

Craig

[Joe R.]

Re: 1967 300hp Alternator Belt

Craig,

If you are trying to put a repo belt on your 67 that is probably the problem. They come in all numbers, sizes and colors of WRONG! If you are going to drive your 67 on and off a trailer, they will be fine! If you drive it like you are a Corvette Enthusiast you better find some place that sells Gates Belts.

JR

[Jeff M.]

Re: 1967 300hp Alternator Belt

Craig,
I have the same engine on a survivor and the belt has the following stamp on it. " GM3847710 53.25X380 5-0757 Hopefully this will help.
Jeff

[Jeff M.]

Re: 1967 300hp Alternator Belt

Craig,
Here's a bad picture of the alt. brkt if it helps.
Jeff

[Henry S.]

Re: 1967 300hp Alternator Belt

Craig,
Try doing a search of the archives. I have a 67 300HP no options and last year had the same problem. However I can't remember exactly what all was discussed. I did a search and found a couple other guys with the same problem. I got the "correct" belt (Quantra) through LIC but when I put it on (or tried to) it also was too short. One problem I thought may have affected mine was the fact I had aluminum valve covers instead of the steel. I thought maybe they stuck up a little higher (when I did get the belt on the alternator was right up against the V.C.). I ended up getting a belt that was an inch or so longer. If and when I decide to get mine judged I'll cross that road then but for now thw replacement belt works just fine. Good luck, Dave

[Henry S.]

Re: 1967 300hp Alternator Belt

Craig,
Try this link: https://www.forums.ncrs.org/showthre...hlight=HP+belt

Dave

[Craig S.]

Re: 1967 300hp Alternator Belt

Jeff,
Thanks for the pic. Thats what my motor looked like before I started the restoration (I often wonder if I should have left mine alone, but that is a conversation for another thread).

Can you confirm your pulley sizes for the crank and water pump (numbers would be great too but I'm not sure if you can see them with the motor in the car). I think this would solve my mystery.

Thanks
Craig

[John H.]

Re: 1967 300hp Alternator Belt

I also have a '67 300hp with the original pulleys, and the Quanta repro belt fits fine - the alternator adjustment is right in the center of the slot in the brace. Maybe I was just lucky.

[Craig S.]

Re: 1967 300hp Alternator Belt

Hi John,
Thanks for the pic. Can you confirm your pulley sizes for the crank and water pump (numbers would be great too but I'm not sure if you can see them with the motor in the car)

[John H.]

Re: 1967 300hp Alternator Belt

Craig -

Pulleys are originals:

3755820 Crank
3905595 Water Pump
3909815 Alternator

[Peter L.]

Re: 1967 300hp Alternator Belt

Craig - Seems there have been a number of customers satisfied with the reproduction belts and an equal number that have not had satifactory results and of those who have not been satisfied it looks like the belts have the "correct" belt number for the application but either been too long or too short. So, since the pulleys on your 67 327 300hp engine appear to be correct, could it possibly be that the belt you received is too short? Pete

[Jeff M.]

Re: 1967 300hp Alternator Belt

Craig,
The best I can tell is the crank pulley is around 6 3/4" to 6 7/8" diameter and the water pump pulley is around 22 1/2" all the way around the edge (circumference). Its kind of tough by yourself. If you need better measurements let me know and I will get some help.
Jeff