73-87chevytrucks.com

73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: Gandalf1969 on July 20, 2010, 09:50:58 pm

Title: 1ZN7 Optional Axle Ratio RPO
Post by: Gandalf1969 on July 20, 2010, 09:50:58 pm

Anyone know what rear-end this code refers to?  Ratio?  Posi?

Taken direct from the RPO code label on my new '73 SWB 454
"1ZN7 Optional Axle Ratio"

I cannot find a reference to it anywhere on the web.  I noted all my codes started with a "1" so I dropped that and found many of my other codes (such as 1C60 for a/c) came up.  Still nothing for "ZN7" though.

Anyone seen this code?

G.

Title: Re: 1ZN7 Optional Axle Ratio RPO
Post by: Irish_Alley on July 20, 2010, 11:53:56 pm

cant help you out with the code but can tell you the only way to tell what you have is if you take the cover off and see. code is only what came stock not what/if it has been changed

Title: Re: 1ZN7 Optional Axle Ratio RPO
Post by: Gandalf1969 on July 25, 2010, 10:33:39 am

Thanks but I'm more interested in the codes and history - wondering if anyone else has or has seen this code and figuring out what it was from the factory.

Title: Re: 1ZN7 Optional Axle Ratio RPO
Post by: VileZambonie on July 25, 2010, 06:14:55 pm

Take a pic of the spid label please. As far as I can see it is a towing package.

Title: Re: 1ZN7 Optional Axle Ratio RPO
Post by: Gandalf1969 on July 25, 2010, 09:05:53 pm

Attached