Intake Manifold Casting Date for '71 LS5

[MIke G #33811]

I was just checking the some dates on my '71 LS5 Roadster. The car's SN# is 107935 so it's a later January '71 car (295 cars from the last of the month). The intake manifold casting date was A1471 which I guess is January 14, 71. When I took the door panels off today, the dates on the inside of the door panels were January 13 one of them and January 21 on the other.

First question, can the casting date on the intake be that close i.e. two weeks from the final assembly. You would think that it would take time to actually cast the part, assemble the engine, ship the engine and put it in the car. Could this have happened in less than two weeks?

Second, is it normal for the door panels to have different dates on them?

Thanks.

[Bill Clupper]

Re: Intake Manifold Casting Date for '71 LS5

With respect to the engine, the relevant date is the engine assembly date. The casting plants were located fairly close to the engine plant and the plants used a LIFO (last in first out) inventory system for many parts, so as long as the casting date is prior to the engine assembly date, it is a possibility. Likewise the door panels were batched, so right-side left side uniformity in dates of manufacture of the door pad would be random in occurance

[Craig S.]

Re: Intake Manifold Casting Date for '71 LS5

Bill - I can verify what you state about LIFO. I have a 67 L79 KH car with an engine block cast date of Feb 23 1967 at 8:00 AM, and an engine stamp asm date of Feb 24. I was very worried about how close the block casting was to the stamp date, but have since had my stamp pad verified and included in the stamp pad registry by Al Grenning, who has verified I have an original engine based on the stamping characteristics of the adjacent car serial numbers in his registry. This was a HUGE relief on my part to verify the engine. Thx!....Craig...