Date Coded Parts

[Raymond W.]

I'm interested in learning more about date coded parts for a car with a build date of Jan. 11, 1974 equipped as follows; 454ci, 4 speed, air cond, power brakes, and manual steering. Is there a date "range" for such parts as; power brake master cylinder, air injection pump & mounting bracket, fiberboard tray, etc.? If so, would they be similar to the date range for an outside rear view mirror, i.e., within 6 months before approx. build date? I'm relying on my TIM & JG for casting numbers but I'm not clear on the date codes. Any further insights on this would be appreciated.

[Patrick H.]

Re: Date Coded Parts

Ray,

While there are exceptions, and seemingly one one every car, it is my experience with both my 71 and 72 that the vast majority of the original, dated parts were made in the month, at most 6 weeks, prior to its build date. This would include motor, trans, starter, carb, AC compressor, power brake booster, etc. The 6 month window is a generalization as for some rare/low build number options it is the norm (or for 67 300 horse intakes). However, St. Louis (and GM in general) tried to stay with a "Just-in-Time" program even if they didn't call it that.

The only exceptions I have seen on my own cars are the water pump and alternator on the 71. August 70 and January 71 on a mid June 71 car.

I would expect that for your 74 it would be very similar, as none of the options you list were particularly low in number and would have been installed in Corvettes on a daily basis.

Patrick

[Chas Henderson #28127]

Re: Date Coded Parts

Keep in mind that on the 1971s' there was a nine week strike. My dec. 70 built 71 has quit a few parts dated in the Aug-Sept time frame. With out the strike, my car would have been an Oct car. My engine is the major exception (at least in stamping as most of the major components are older) It was stamped 12-01-70 and the car was built 12-14-70 and cast Nov 5,70. So it is possible to have a whole range of dated parts.

Chasman