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1970 442 Rotor Help

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Old January 14th, 2015, 11:10 AM
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1970 442 Rotor Help
I have two different styles of rotors. One has a groove in the center of the machined face and the other one does not. The one with the groove has a number on it (38505R). The one without a groove has no number. Does anyone know if the one with the number is a stock rotor?

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Old January 14th, 2015, 03:18 PM
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Rick I think that is a Raybestos part number
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Old January 14th, 2015, 04:15 PM
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pretty sure all the factory rotors had that groove in the center. That was a wear indicator when there was no more groove it's time to replace the rotor. Someone correct me if I'm wrong?
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Old January 14th, 2015, 06:40 PM
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Originally Posted by oldspackrat
pretty sure all the factory rotors had that groove in the center. That was a wear indicator when there was no more groove it's time to replace the rotor. Someone correct me if I'm wrong?
Scott,
Do you have one of the grooved type?

Rick
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Old January 14th, 2015, 06:56 PM
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I think I just sold my last set a couple weeks ago, but might have one left in another building. Will find out soon.
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Old January 14th, 2015, 08:05 PM
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Originally Posted by oldspackrat
pretty sure all the factory rotors had that groove in the center. That was a wear indicator when there was no more groove it's time to replace the rotor. Someone correct me if I'm wrong?
I believe that is correct.
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Old January 14th, 2015, 09:17 PM
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I still remember these friggin' part numbers


That's amazing!!
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Old January 15th, 2015, 02:57 AM
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I guess I can tell mine is a low mileage car! Still has the groove in both rotors and original T-3 bulbs across the front.

Pat
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Old January 15th, 2015, 01:29 PM
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Originally Posted by 1968_Post
GM used 2 rotors back in the day... the numbers were 1852722 and 1971247. Both show up occasionally on eBay (there's a few on eBay right now of both numbers). They were superceded back and forth for a while, and we used either number, depending on which we could buy cheaper from our Delco supplier.

The scary thing is I haven't been a Bowtie parts guy since the early 70's and I still remember these friggin' part numbers (plus a bunch more...). Definitely a bunch of useless information stuck in my head!

http://www.ebay.com/sch/i.html?_from...2722+&_sacat=0

I didn't know you could use those for brake rotors
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Old January 15th, 2015, 01:57 PM
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Rick,
I found 2 decent to good looking originals.
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Old January 15th, 2015, 02:06 PM
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Originally Posted by Octania
http://www.ebay.com/sch/i.html?_from...2722+&_sacat=0

I didn't know you could use those for brake rotors
Yeah,
I don't think those are going to work. In all fairness, I guess I really didn't specify that I was looking for brake rotors. Still pretty funny!
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Old January 15th, 2015, 02:08 PM
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Originally Posted by oldspackrat
Rick,
I found 2 decent to good looking originals.
Scott,
I'll check them out Sunday. Hope the weather cooperates.
Did you get my revised...revised parts list today?
Rick
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Old January 15th, 2015, 03:09 PM
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Originally Posted by Octania
http://www.ebay.com/sch/i.html?_from...2722+&_sacat=0

I didn't know you could use those for brake rotors
LOl... Duh! That was pretty stupid! Yeah, they'll stop a car dead, but in quite a different manner.

I have no clue what I was thinking... I think I'll go hide in the shadows now.
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