Orignal bolts (1963 Alternator bracket to exhaust manifold)

[Richard G.]

I took these pictures of the Alternator bracket to exhaust manifold bolts today.
They are 7/16 diameter and two different lengths.
I believe they are correct for my 1963.
I would like to know what the correct finish would have been.



The bolts do not have matching head markings, not that unusual from what I have read.



Thanks in advance.
Rick

[Joe L.]

Re: Orignal bolts (1963 Alternator bracket to exhaust manifold)

Rick------


The bolts, GM #122260 and 186727 were zinc plated. The different headmarks are not unusual. In fact, for different length bolts such as these, different headmarkings are more common than not.

[Joe R.]

Re: Orignal bolts (1963 Alternator bracket to exhaust manifold)

Joe,

Don't you find it a bit odd that a grade 3 standard and a grade 8 bolt is used on the same application???????

JR

[Richard G.]

Re: Orignal bolts (1963 Alternator bracket to exhaust manifold)

Yes it is odd "the grade 8 is in this application". I would say that these were absolutely original except I did have it apart once years ago. I was careful to put everything back exactly as I found it but mistakes are made. The bolts are GM and seem to be the perfect length for the application.

What about the small screw that retains the bracket for the heater hose? What finish would that have been? Right now its powder coated black.
Not exactly what GM would have done in 63!
I am guessing the alternator bolt spacer would have been a natural or black phosphate finish?

I am wrapping up the details on the frame and hope to have it finished soon. Then starting the motor for the first time after all these years.
Should be fun.
Rick

[David L.]

Re: Orignal bolts (1963 Alternator bracket to exhaust manifold)

Rick,

It's nice to see that you have the correct alternator bracket for your 63.

Dave

[Edward J.]

Re: Orignal bolts (1963 Alternator bracket to exhaust manifold)

Rick, my 63 has the exact bolts you have for the bracket. one grade 3 and one grade 8 WB head marks, all bolts where Zinc plating.

[Joe L.]

Re: Orignal bolts (1963 Alternator bracket to exhaust manifold)

Joe,

Don't you find it a bit odd that a grade 3 standard and a grade 8 bolt is used on the same application???????

JR

JR------


Yes, it's a bit unusual. However, the GM #122260 was a GM 260-M material grade bolt (no radial lines) and the GM #186727 was a GM 300-M material grade bolt (6 radial lines). So, the bolts are exactly as they should be.

[Timothy B.]

Re: Orignal bolts (1963 Alternator bracket to exhaust manifold)

Richard,

Can you measure the length of those two bolts and post.

[Joe R.]

Re: Orignal bolts (1963 Alternator bracket to exhaust manifold)

Yes it is odd "the grade 8 is in this application". I would say that these were absolutely original except I did have it apart once years ago. I was careful to put everything back exactly as I found it but mistakes are made. The bolts are GM and seem to be the perfect length for the application.

What about the small screw that retains the bracket for the heater hose? What finish would that have been? Right now its powder coated black.
Not exactly what GM would have done in 63!
I am guessing the alternator bolt spacer would have been a natural or black phosphate finish?

I am wrapping up the details on the frame and hope to have it finished soon. Then starting the motor for the first time after all these years.
Should be fun.
Rick

Richard,

The bolt for the heater hose bracket was cad or zinc plated and the alternator spacer was either black phosphate or natural. I believe the bolt for the alternator to be either cad or zinc plated also.

JR

[Richard G.]

Re: Orignal bolts (1963 Alternator bracket to exhaust manifold)

Dave;
Really nice drawing! Thanks for sharing. Another 63 only item I didn't know about.
Below is a picture of the side of the bolts. I found the lengths Interesting because they were in increments of 1/8" not the 1/4" I am used to.
1) Short bolt is 1-1/8
2) Long bolt (grade 8) is 1-3/8 in length.



I could find nothing left of the original finish. Bolts are in surprising good shape for being installed on a hot exhaust manifolds.
Maybe the hardening helps?

Below is another picture of the bolt heads, after hitting with a power wire brush. Sure changed the way they look.

Rick