When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
First off is identifying the production date of your car. Obviously the distributor must have been made before this date; a few days to 6 months prior is the NCRS's rough guideline, but I think 2 weeks to 3 months prior is probably much more common. The only date on the distributor housing is stamped into the aluminum tag in the groove just above the intake manifold mounting boss. The tag will have "Delco Remy", the distributor # matching the engine option, last digit for year, letter for month, and 2 digit day. The letters began with A in January through L in December.
Pics below from eBay listing for a '72 350/200hp, made Jan. 26, 1972:
Last edited by barkingrats; Nov 10, 2022 at 09:29 PM.
From: At my Bar drinking and wrenching in Lafayette Colorado
Originally Posted by Mrvettenick
Does anyone know what the common dates for 1972 distributors were? I just want to make sure I get a distributor with a proper date code.
Delco produced distributors 7 days a week, every day of the year. There is no "common date" that distributors were built. Pick a date - they made a thousand that day. Those distributors were installed into engines anywhere from a few days to a few months from the assembly date of the distributor, and those assembled engines were installed into cars anywhere from a few days to a few months from the assembly date of the engine. Using some basic reverse arithmetic, the distributor may have been assembled a few days to 6 months prior to the build date of the engine, and the engine may have been built anywhere from a few days to 6 months prior to the build date of the car. Depending on the build date of the engine, the "correct" build date on the distributor can be anywhere from 1 week to almost a year prior to the build date of the car.
On several C2/C3 cars I have owned every date coded part that I knew with 99.9% certainty was original to the car from the factory was dated 1-6 weeks prior to the engine or car build date. Most of these parts were still warm from the foundry when they hit the GM assembly line. Stuff didn't set around on shelfs and that special BB engine didn't set over against the wall for eight months waiting to be installed in that that special SB equipped car. Likewise, GM never ran out of mid-year SB hoods and had to install that special BB hood over a 327/350 engine.
Current 1973 L82 car
Date sold at dealership 16 June 1973
Estimated car build date 10 June 1973
Body build date 8 June 1973
Engine assembly date 1 June 1973
Heads date 23 May 1973
Intake date 31 May 1973
Q-Jet date 2 May 1973
Clutch Fan date 28 April 1973
Distributor date 26 April 1973
When chasing that date coded part you need so badly don't ask the seller how much, ask the seller how much should I send you. I played this game on a 65 I owned, it got stupid expensive real fast.
Agreed. My two predominantly original engines have all of the dated parts within 2 weeks of the final assembly. GM wouldn't have made parts to sit around in inventory. There are, of course, anomalies that have been documented but typical production was much tighter than 6 months back.
Mrvettnick, the aluminum tag is the only part of the distributor that carries a date, however there were some running physical changes to the main casting over the years. The tags are reproduced, but I'm not familiar with sources and accuracy. For a '72 casting, you need to have that small hole opposite the tach drive gear (seen in the last pic above). If you don't have the NCRS Judging Guide for '70-72, it's a good resource for typical production parts descriptions.
Thanks much guys. For some reason I thought they made distributors in batches like the Camaro, which I know for like 1970 there were like 4 "common" dates that they were made. In that case, you just can't pick a date.
I played this game on a 65 I owned, it got stupid expensive real fast. 
