67 GT500 alternator pulley

[shelbydoug]

Does that pulley supposed to have an engineering number stamped into it?

Are either of these two the right one?

One is cut much deeper for the retaining nut.

Neither has an id stamped into it?

[Royce Peterson]

Looks right to me. Here's what Jack says:

"This is a standard service double sheave pulley that is similar to the C9AF-10A352-C used on all many Fords including the 428 S/CJ starting sometime in late 1968 or early 1969. This pulley also replaces the earlier C5AF-10A352-J & J2 pulley that is a bit smaller in diameter.  No engineering numbers are stamped on this pulley."


https://www.deadnutson.com/1965-70-double-sheave-alternator-pulley-service-pulley-w-o-die-stamp/

[roddster]

  Got to ask:  Is this pulley larger in diameter?  Let's say than the one you would get with a 390 with air?

[Royce Peterson]

The dual sheave cast iron pulley is used on non - AC vehicles only. It would have been used on 390 applications as well. I have not put them side by side in many years but from memory the single sheave stamped steel A/C version is a little smaller in diameter.

  Got to ask:  Is this pulley larger in diameter?  Let's say than the one you would get with a 390 with air?

[shelbydoug]

Looks right to me. Here's what Jack says:

"This is a standard service double sheave pulley that is similar to the C9AF-10A352-C used on all many Fords including the 428 S/CJ starting sometime in late 1968 or early 1969. This pulley also replaces the earlier C5AF-10A352-J & J2 pulley that is a bit smaller in diameter.  No engineering numbers are stamped on this pulley."


https://www.deadnutson.com/1965-70-double-sheave-alternator-pulley-service-pulley-w-o-die-stamp/

I appreciate the information. I didn't have that page bookmarked.

Did you notice the difference in the pocket depth? These are two different pulleys.


I think the shallow pocket IS the FORD Service part? I'm very sure that's where I got it from 30 years ago. 


I don't have an alternator here to try it on yet and if the alternator's drive shaft is long enough to mount it then there is no problem I think?

The alternator is out getting rebuilt and detailed and won't be back for two or three weeks so my curiosity is causing trouble again? 

[Bob Gaines]

Does that pulley supposed to have an engineering number stamped into it?

Are either of these two the right one?

One is cut much deeper for the retaining nut.

Neither has an id stamped into it?

I have not seen the style in your first picture with the key way used. I have seen the style in your second picture but marked pulley 1 with the flat front surface used on 67 GT500's.I have seen it with the short bevel on the inside edge and more commonly without the bevel on the inside edge like on the left in the picture I posted. I have seen both styles with stamped engineering numbers and also without. There is another double pulley example that is the most common one I see used on 69 Shelby's that I posted a picture of on the right. The more common 69 pulley(from my perspective) has a contoured front surface instead of a flat surface . This contoured front surface double pulley style was not used on 67 GT500's from the factory. .

[Royce Peterson]

Last night I went through my rusty alternator pile and found two pulleys like the second picture the OP posted. They indeed have the part number engraved on the rear side and no keyway. I will clean them up enough to get photos.

On the subject of diameter the dual sheave pulley from Dead Nuts On is maybe 1/16" bigger OD than the OEM ones with the slight bevel and the part number engraving. I also found a single sheave stamped pulley from an A/C version, it is actually a little LARGER diameter not smaller as I earlier speculated.

[Special Ed]

The contoured c9af pulley (in bobs photo on the right) was NOT used from the factory on 69-70 shelby gt500s. The contoured pulley was  a later service replacement part from what i seen and may have been used on some other later ford products but i have never seen it used on 69 -70 shelby gt500s. In 69 the 428cjs used the new c9af flat alt pulley that was a bigger diameter than the 65-68 c5af pulley. I found new take off c9af alt pulleys in old ford dealerships and they had black paint on the front face side but not sure if that was a color code to id the pulley or to id the alternator assembly when it was completed and tested.

[Royce Peterson]

Here are some photos comparing the DNO part with the assembly line version. This one came from an unrestored 1968 Cougar GT-E with 428CJ engine. The alternator is a typical 1968 Autolite 42 AMP version with teardrop shape casting on the back and no imprint for part number and no Autolite word cast on the back. The OEM pulley measures 2 9/16" diameter. One has a black finish, the other one (not pictured) was gold cad plated. The other one was in much better condition so it is in an Evaporust bath.

The DNO part has no bevel on the front and appears to be finished in zinc nickel with trivalent chromate finish so it will resemble gold cad plating but clearly it is much shinier than a OEM part would have been. It measures 2 5/8" diameter.

The 1965 - 68 assembly line version has the part number engraved or stamped on the rear surface.

[shelbydoug]

Great pics.

Here's a side view of the one with the key from the side. No number on it.

Anyone want it for $30?