I would normally use a month but wanted to ask the experts here on what seems to be the normal or average time difference between date codes on exhaust manifolds to the cars build week? If it makes a difference in time periods of gen 1 Camaro's the question deals with the 68 model year where the camaro was built the 3rd week in Jan68.
Thanks in advance,

Chick,
Not positive on 68, but my "06A" 69Z28 ( built June 18 ) has ex manifolds dated E-23-9, and E-28-9. They are original, engine stamp is V0527DZ.
I would think that late Dec to early Jan would be perfect for your 01C car.
Hope this helps.

I thought the exhaust manifolds were installed as part of the engine build, so it should match the engine, not the body.

Nope, Exh manifolds were installed at the vehicle assembly plant, as were distributors, carbs and most other bolt on items like PS pumps, alternators, A/c etc.

I thought the only difference between a Camaro b/b and Chevelle b/b was the manifolds. If they are installed later, why carry different codes? Camaro and Nova share codes.

Chick .... my '68 04C (April, week 3) car has C-21-8 & C-25-8 exhaust manifolds ... about the same lag as rszmjt.

Chick .... my '68 04C (April, week 3) car has C-21-8 & C-25-8 exhaust manifolds ... about the same lag as rszmjt.

Thanks "RealSS396" and "rsmjt" :thumbsup: Appreciate the help :D
Now the hunt for some late Dec. to early Jan manifolds.
:beers:
thanks again,