Topic: 1968 San Jose GT 390 Front Rotors

[bullitt68]

Just curious as I hadn't noticed before, but I have two different rotors. Not sure what they are different. No markings or stamps anywhere. I believe that my car should also have the 2 pce rotors. Do the factory rotors have markings and stamps? A reference photo would be great.

Thanks

[J_Speegle]

Easy to see that you have at least one replacement rotor. Will see if I've got some examples to share. Don't recall many pretty pictures of the detail though 

Know there are at least a couple of versions of the rotors installed on 69 cars. Not sure if that is tied to the car assembly plant and in turn the different suppliers or something else.

[Bossbill]

The replacement rotor is the one piece looking affair. Your pic 2 & 4.

I believe the 68 rotors are similar to 67s with a few differences.
The 68 original assembly rotors have a square cutout in the hub face along with a drilled hole like 67. Rather than having windows in the rotor portion like 67, the windows are gone and are solid. Also, the thickness and throwaway dimension is different between the two.

Here are a few pics of what I'm told are original 68 assembly line rotors.

[bullitt68]

The replacement rotor is the one piece looking affair. Your pic 2 & 4.

I believe the 68 rotors are similar to 67s with a few differences.
The 68 original assembly rotors have a square cutout in the hub face along with a drilled hole like 67. Rather than having windows in the rotor portion like 67, the windows are gone and are solid. Also, the thickness and throwaway dimension is different between the two.

Here are a few pics of what I'm told are original 68 assembly line rotors.

Thanks Jeff. If the photo in 2 & 4 are the replacement rotors what rotors are in photo 1 & 3. In the photos your posted, are those what they refer to as 2 piece rotors, or was that just 1967.

[Bob Gaines]

Thanks Jeff. If the photo in 2 & 4 are the replacement rotors what rotors are in photo 1 & 3. In the photos your posted, are those what they refer to as 2 piece rotors, or was that just 1967.

Rotors in pic 1 and 3 are the 2 piece style rotors. The 2 pc style rotors were typical on 65 on up through the 70's Mustangs . Even replacements were typically 2 pc style up until the 90's when the more cost efficient on piece style came into mainstream use.   

[bullitt68]

Rotors in pic 1 and 3 are the 2 piece style rotors. The 2 pc style rotors were typical on 65 on up through the 70's Mustangs . Even replacements were typically 2 pc style up until the 90's when the more cost efficient on piece style came into mainstream use.

Thanks Bob. So are you saying that the rotor in photo 1&3 is correct for my car or a replacement versions of the 2 piece original one in Jeffs' photos. The one in Jeff's photo look like 2 pieces while the version I have appear to be one piece, but I have never tried to take them apart

[Bob Gaines]

Thanks Bob. So are you saying that the rotor in photo 1&3 is correct for my car or a replacement versions of the 2 piece original one in Jeffs' photos. The one in Jeff's photo look like 2 pieces while the version I have appear to be one piece, but I have never tried to take them apart

The ones in your pic 1 and 3 are definitely 2 pc rotors. They may be service or after market replacements but still 2 pc and more like the factory. The ones in BILL's photos are what the assemblyline typically look like . 2 pc are like the factory the one piece are not. With that said you are better off with some kind of 2 piece rotor compared to the one piece style from a originality stand point and given the expectations you have shared. Another way of saying it is find a pair of 2 piece matching rotors and be done so as to move on to your next issue IMHO . With all do respect you have a lot on your plate and a lot of issues.

[bullitt68]

The ones in your pic 1 and 3 are definitely 2 pc rotors. They may be service or after market replacements but still 2 pc and more like the factory. The ones in BILL's photos are what the assemblyline typically look like . 2 pc are like the factory the one piece are not. With that said you are better off with some kind of 2 piece rotor compared to the one piece style from a originality stand point and given the expectations you have shared. Another way of saying it is find a pair of 2 piece matching rotors and be done so as to move on to your next issue IMHO . With all do respect you have a lot on your plate and a lot of issues.

Thanks Bob. As always appreciate all your advice and feedback

[Bossbill]

Were these 2 piece rotors on your car?

I stole this from VMF:
New rotor thickness for 67 is .810 in and minimum thickness is .780 in.
New rotor thickness for 68 and up is .935 in and minimum thickness is .875 in.

If the rotors are at or past minimum NPD has 65-67, but not 68-up except in the one piece.

[bullitt68]

Were these 2 piece rotors on your car?

I stole this from VMF:
New rotor thickness for 67 is .810 in and minimum thickness is .780 in.
New rotor thickness for 68 and up is .935 in and minimum thickness is .875 in.

If the rotors are at or past minimum NPD has 65-67, but not 68-up except in the one piece.

Thanks Bill appreciate it

[bullitt68]

Were these 2 piece rotors on your car?

I stole this from VMF:
New rotor thickness for 67 is .810 in and minimum thickness is .780 in.
New rotor thickness for 68 and up is .935 in and minimum thickness is .875 in.

If the rotors are at or past minimum NPD has 65-67, but not 68-up except in the one piece.

Hi Bill Both these rotors came on my car. I measured them and they must be pretty new judging by the thickness.

[Bossbill]

Great news on the two piece.
Not sure what you want to do with the one piece.

[bullitt68]

Great news on the two piece.
Not sure what you want to do with the one piece.

Well in a perfect world I can find another two piece rotor somewhere. Otherwise I will need to find a new pair somewhere

[Bossbill]

NPD part number 1192-A is a one piece replacement.
It should match yours.
If it doesn't match 100% looks-wise just buy both for $106.

[bullitt68]

NPD part number 1192-A is a one piece replacement.
It should match yours.
If it doesn't match 100% looks-wise just buy both for $106.

Sorry that was a typo meant to say two piece rotor, which would be more correct if I can't find original/correct two piece rotors