1971 Cuda manual drum brake master cylinder cover correct finish

[76orangewagon]

I am trying to figure out the correct finish for my 1971 Cuda Master cylinder cover. I soaked mine in Evaporust and refinished the housing but I'm not 100% on the cover finish. I thought it would be a yellow zinc but at Mecum last week I saw one that was NOS and part of the Steven Juliano collection and it didn't seem to have any finish on it. The first 2 pictures are of the NOS one and the next 2 are mine.

[anlauto]

You can't really go by "NOS" parts...you need to study survivor cars with the original "assembly line" parts.

It's like UCA's when the were made for service they were usually painted or primed so they wouldn't rust, but when they went straight to the assembly line they were left bare with maybe a thin coat of cosmoline

[cudaize]

I put a NOS black phosphate one on my car with vents like you have in your first 2 pictures.  The second one you show that says DOT 3 I don't believe is proper for 71 production year.  It should have the older classification which I believe is 70R3 or something like that.

Attached is a photo of a 72 dart that was on Ebay some years back with 28 miles and it looks to have a black phosphate cap.  Most of the cars I've seen that I believe had the original master seemed to have this cap.

[cudaize]

Here's a photo of my master cylinder installed.

[76orangewagon]

I put a NOS black phosphate one on my car with vents like you have in your first 2 pictures.  The second one you show that says DOT 3 I don't believe is proper for 71 production year.  It should have the older classification which I believe is 70R3 or something like that.

Attached is a photo of a 72 dart that was on Ebay some years back with 28 miles and it looks to have a black phosphate cap.  Most of the cars I've seen that I believe had the original master seemed to have this cap.

I agree 100% that the cap is wrong, maybe I should search for an original cap before worrying about re-plating the wrong one. Thanks for the input.

[cudaize]

Here's a picture of an NOS 70 R 3 version I have.  I believe there was a version of this cap (no venting between the front and rear reservoirs) with no printing at all that some have said were found on production line examples.  Also there is an intermediary between this one and the DOT 3 version which I believe called out a J1703 standard. 

[cudaize]

Here's a better detail of the cap that I put on my master cylinder.  The black one is an NOS one, I bought 2 and used the nicest one on the car.  It's like a phosphate which a heavy oil or grease. 

The gold one is from a rebuilt master I had at one point.