C3-1971 Exhaust Manifold Date Code?

[Greg F.]

My exhaust manifolds are original or so they seem...

The casting number is correct for each one. I was checking the date codes and came up with the following two codes on the inside portion of each manifold (side facing the heads):

A27 (Jan 27th?) (passenger side)
L1 (Dec 1st?) (driver's side)

My Technical Manual states there should be a "1" or a "0" to represent the year. My engine was assembled on Feb 9th, so these dates should have a "1" or a "0" at the end, correct??? Is the date located somewhere else?

Thanks,
Greg

[Terry M.]

Re: C3-1971 Exhaust Manifold Date Code?

Are you sure that note in the manual is not referring to big block exhaust manifolds? In the early C3 era small block exhaust manifolds had no year designation.

[Harmon C.]

Re: C3-1971 Exhaust Manifold Date Code?

My exhaust manifolds are original or so they seem...

The casting number is correct for each one. I was checking the date codes and came up with the following two codes on the inside portion of each manifold (side facing the heads):

A27 (Jan 27th?) (passenger side)
L1 (Dec 1st?) (driver's side)

My Technical Manual states there should be a "1" or a "0" to represent the year. My engine was assembled on Feb 9th, so these dates should have a "1" or a "0" at the end, correct??? Is the date located somewhere else?

Thanks,
Greg

Small block exhaust manifolds are only dated with the month on all of them I have seen.

[Greg F.]

Re: C3-1971 Exhaust Manifold Date Code?

I just looked again. It has section about exhaust manifolds and the casting number, it's states to look in Section 27 for the date codes. The last line talks about the small block casting # of 3970010 (which is mine).

"has the year indicated by one numberal (example E152 = May 15, 1972)."

I guess the odd part about this page is it doesn't mention exhaust manifolds....only engine blocks, distributor and alternators...maybe it's a mistake in the TM for 70-72????

Thanks.

[Greg F.]

Re: C3-1971 Exhaust Manifold Date Code?

Nevermind....I went back to the Exhaust manifold section and it states the date codes are the same WITHOUT the year at the end. I misread it.

Thanks and sorry about that...!

[Terry M.]

Re: C3-1971 Exhaust Manifold Date Code?

No mistake -- unless things have changed more than I think, we don't judge exhaust manifold dates on 1869-1972 Corvettes. Thus the information in the TIM&JG is along the lines of Technical Information -- NOT Judging.