[firebird1970]

I've got a 70 bird and have found these numbers 51370N2 stamped on the subframe on the drivers side underneath the floor. Was woundering what they are. Is 513 the month and day, 70 the year, N for Norwood, and 2 firebird. Curious.

[firebird1970]

So I take it no one knows.

[giles]

Firebird1970, I think you are right that it is a date code. My Norwood built '71 has "32571S1" at the rear outside edge of the LH side rail. Unfortunately the "S" would seem to shoot a hole in your "N" for Norwood theory. Ditto the "2" for Firebird. Not sure what the "1", "2", "S" or "N" might stand for at this point.

[eaglesan13]

I have an extra subframe off a 70 Formula in the garage and I don't see any stampings where you describe. Can you give me a better idea of where they are?

[Brewster]

Yes, can the numbers be seen without disassemble ? Mirror, or digital camera hits due to location.
Thanks

[firebird1970]

Their is no disassemble they are on the driver side frame rail rear outside edge by the bushing.

[eaglesan13]

Okay I finally found them. They are on the outside edge of the drivers side frame rail all the way at the back edge. I tried taking pictures but they don't come out. With flash it's too much light and without it's too dark to see the numbers. Anyway, the extra subrame I have was from a 70 Formula and the frame numbers are: 6I970N2. The numbers on my 70 trans am are: 4 670N1. I have no idea what they mean.

[69 T/A]

My '70 T/A has: 7 770S2

[Norwood]

My 70 4sp Norwood car has: 7 670S2

[keith k]

Definitely date codes. Would be interesting if those who have posted their frame dates could post their trim tag body dates just to see how close they are. My old TA had a 62070 subframe on an 06E (last week in June) body.

[eaglesan13]

Keith,

70 trans am, frame number 4 670N1, Van Nyes car with a trim tag date of 04B, built on April 13, 1970. But, you knew that

I guess the frame number could mean April 6, 1970 which is possible for my car. Since your car was built the same day maybe your frame date is close to mine. The closest date code to the build date on my car is the rear end which is dated April 8, 1970.

I don't have any info on my extra frame since I never saw the car it came off of.

FYI, mine is a 4 speed car, maybe the N/S or the 1/2 are for standard or automatic. Didn't they use different transmission crossmembers? Maybe they coded the frame so they would know which crossmember to attach to it since this was probably a sub-assembly. Just a guess.

Originally Posted by keith k

Definitely date codes. Would be interesting if those who have posted their frame dates could post their trim tag body dates just to see how close they are. My old TA had a 62070 subframe on an 06E (last week in June) body.

[keith k]

Originally Posted by eaglesan13

I guess the frame number could mean April 6, 1970 which is possible for my car. Since your car was built the same day maybe your frame date is close to mine. The closest date code to the build date on my car is the rear end which is dated April 8, 1970.

I don't have any info on my extra frame since I never saw the car it came off of.

FYI, mine is a 4 speed car, maybe the N/S or the 1/2 are for standard or automatic. Didn't they use different transmission crossmembers? Maybe they coded the frame so they would know which crossmember to attach to it since this was probably a sub-assembly. Just a guess.

Chris,
That doesn't sound like a bad guess for the N's and S's.

I would have noted the subframe date on my current TA (I had it written down for my old car), but after a minute of scuffing up the subframe on it yesterday, I couldn't find it -- lots of accumulated dirt with paint overspray mixed in. Maybe I didn't look in the right place....

Does anyone have a pic they can post that shows approximately where it is?

[GRNMTGOAT]

Keith, its about 1/2'' in from and parallel to the angled end of the frame.
My car is Auto 1970 built Norwood 05B, frame code is 5 770N1
Bruce.

[eaglesan13]

Well a date code of May 7, 1970 is perfect for an 05B build date. However, since your car is a Norwood built auto car and mine is a Van Nyes manual trans, and since they both have an N1, I guess that blows a hole in my theory about the N/S or 1/2 being for stick or auto.

But, if the frame was a sub assembly maybe it was coded for the sway bar size.

Originally Posted by GRNMTGOAT

Keith, its about 1/2'' in from and parallel to the angled end of the frame.
My car is Auto 1970 built Norwood 05B, frame code is 5 770N1
Bruce.

[firebird1970]

keith K curious to what the numbers are on your 70 formula.

[eaglesan13]

Here is a picture off my extra subframe showing the location of the numbers. This is the outside of the drivers side frame rail at the rear.

[keith k]

Originally Posted by firebird1970

keith K curious to what the numbers are on your 70 formula.

My Formula is in barn hibernation about 30 minutes from my house. I'll see if I can get a number off it the next time I'm out there....

[cnc]

my 70 esprit
20670S2

[Tunas73TA]

My 73 doesnt have any letters...all numbers..Still correct?

[superdutybob]

My guess would be that the first two or three numbers are julian date for the day of the year. The 70 would be the year, as in 1970. The N1 or S2 or whatever combination could be the plant that built the subframe and the shift that it was built on.