Firewall tag

[deadeyecop1]

I found a tag on the firewall and need some help figuring out what it means
M63A-J-75-1 323-5
427 405
I was told this car had a 427 installed in Atlanta factory after production.
Vin says a 390
Any help would be great

[kirk]

What kind of car are you talking about? What's the VIN?

[deadeyecop1]

It is a 64 mercury marauder vin z47y510963.
The tag was found screwed in the middle of the firewall

[kirk]

I found a tag on the firewall and need some help figuring out what it means
M63A-J-75-1 323-5
427 405
I was told this car had a 427 installed in Atlanta factory after production.
Vin says a 390
Any help would be great

I don't have any decoder for this tag specifically. This is what little I can tell you;
I think M = Mercury
63A = Monterey Marauder 2-door
J = Carnival Red exterior
75 = Red interior

I'm coming up blank on the rest of it.

Y = 390 2V - 250 HP

[deadeyecop1]

Kirk, that matches the door tag. The mystery is the -1 and the 323-5. The 427 and 405 are not factory stamped into the metal. they were stamped using a metal punch set.
The previous owner told me it has a 427 installed after production in the Atlanta factory

thanks

[kirk]

The previous owner told me it has a 427 installed after production in the Atlanta factory

thanks

Does it have cross bolts at the bottom of the block? If not it's not a 427. Having the cross bolts doesn't make it a 427, but is an important clue.

[chief455]

Kirk, that matches the door tag. The mystery is the -1 and the 323-5. The 427 and 405 are not factory stamped into the metal. they were stamped using a metal punch set.
The previous owner told me it has a 427 installed after production in the Atlanta factory

thanks
can you post a picture of the tag?

[deadeyecop1]

Here is the pic if it posts

[sflrainmaker01]

Wow, that looks authentic. But, good luck and free bump for ya!