[GTOh!]

Hi all. Hoping that someone here can point me toward a “correct” fan belt for my ‘67 GTO. I currently have a serrated/cogged belt and I want to best replicate what came from the factory when new.

I ordered a reproduction alternator belt from Quanta but the tech there told me they didn’t buy a license to make the A.I.R. belt because of anticipated sales volumes. According to my measurements, the needed belt measures 15/32” X 70”.

Any help/advice is much appreciated

Thanks

[60sstuff]

I think it may help readers to know what options this ‘67 has besides the A.I.R. Pump.

[GTOh!]

Thanks, 69sstuff.

There are no belt driven optional accessories beyond A.I.R. No p/steering, no air conditioning. I suppose the original owner was a CA resident and didn’t want any optional power-robbing drags on the engine. Alternator has a double groove pulley and A.I.R. pulley is a single groove unit.

Again, I measured the (outside) circumference of the belt as 70”. Width looks to very close to the factory specified 15/32”.

Hope this helps.
Don

[gto4ben]

Your engine compartment looks so roomy! I found the 15/32" belt width to be a little wide on the A.I.R pulley. Your length appears to be 69".

[GTOh!]

Following up on my initial post, I ended up using a 3/8” X 70” belt for the A. I. R. pump and a 3/8” X 57” belt for the alternator. This is inconsistent with factory specs but the 3/8” v belt fits the pulleys perfectly. The belt diameters allowed me to center the pump and the alternator in the center of adjustment.

[428ho4spd]

GTOh!... The factory '67 pulleys were designed for two different width belts. They should sit pretty level with the outer opening of the pulley. Here's what mine looked like with new NAPA belts in the correct widths. Adjusting the belts is a little tricky with the A.I.R. pump.

Sure would be nice if they would upgrade the quality of photo attachments on this forum!

[GTOh!]

Thanks, 428.

Interesting to me is that while a 15/32” belt width is specified for these pulleys, the 3/8” belt fits so much better. The 3/8” belt was much more easily sourced too.

I’ve attached a few pics to show how the 3/8” belt seats perfectly into the water pump, crank, alternator and A. I. R. pump pulleys. Zoom in on belts to see fit detail.

Thanks again to all for advice.

[428ho4spd]

GTOh,

I wanted to clarify that the original belt application is actually 1/2" for alternator and 3/8" for the A.I.R. pump (see attached charts).

It appears that you may have an aftermarket alternator pulley with two 3/8" grooves, that would cause an issue. Also, I see that your alternator adjustment is nearly all the way out where it should be more in the center.

Lastly and not a big deal, but more for "correctness"... your alternator ink stamp code (and possibly the alt stamp number too?) is not correct for this application. This was a unique alternator number used only with this configuration of manual steering and A.I.R. pump. It should be code VD and stamp number 1100768 37A. I was lucky and found a correct dated one for my car. The restorer had another one with a similar date if your interested in pursuing that one?

Grant

[428ho4spd]

GTOh,

I found some better close-up photos of the pulleys and belts that I'll attach here. You can really see the difference in the widths of the crank pulley grooves in the one photo with no belts in place.

Grant