Acceptable date codes

[Monte7071]

I have a LS-5 and the block is dated 1/11/70 the heads are stamped b-71 at first I thought they were the wrong date. But the more I look on other sites it looks like they are correct. Do any of you guys know the dates on your block vs your heads.

[daberry]

6 months is the number used by the corvette guys. So as long as your date codes are before the build date of your car and within 6 months of each other you have a matched set. Dale

[gprimm]

I have come to a slightly different opinion for the 1971 production year dates. The correct answer, of course, is that the dates should be before the car's build date. Based on presentations of Fran Preve, former employee of the Tonawanda, NY engine plant, 1971 was a strange year. Based on what he said, you could have any date prior to that due to the following.

 

In 1986 the Northern Illinois Chevelle Club hosted the National Chevelle Owners Association National Convention in Peoria, IL. Mark Meekins, President of the NCOA invited Fran to speak to us to answer questions. Fran had recently been "given the production information keys" by Chevrolet as a kind of unofficial source for production information. Fran was a long time employee and a Chevrolet racer. He patiently answered many questions, one of which was from me regarding the infamous and yet found LS-6 Monte Carlo (never made per Fran). He was even writing columns in national car magazines on the topic of engine production.

 

In 1971 GM made the decision to reduce their number of SKU's used in the engine production to about 25% of what it was. With that edict the Tonawanda plant went into the inventory, including the repair area, and dumped all the parts into the production. One of our members then piped-up and said he had taken his original small block engine apart, 350-245hp 2-barrel and the heads were 69 production. Fran agreed that this was possible as the engine production line was using whatever was given them.

 

I got to know Fran and over the next few NCOA Conventions we would walk around the show field and listen to people ask about production. Here are two cars that he knew were built from the production information he had, but could not advertise it due to someone trying to duplicate them:

 

1). 1972 El Monte. Yes, in 1992 at the NCOA Convention in Nashville, there was a 1972 El Camino with a Monte Carlo front clip. For sale for $6,000. That night about midnight we were at a table talking and the owner of the El Monte comes to chat. He said he didn't know who did the work but it was done well. Fran asks him "where did you buy it". The answer was Virginia and Fran said that the Baltimore plant had built that El Monte, but it had gotten away. He asked if the owner had taken the door panels off and if so, were there any weld seams. The answers were "yes" to the door panels and "no" to the seams. Fran then said that fits and he would ask the plant production guy from Baltimore to verify the El Monte, but that was probably the car. After telling the owner I would pay $6,000, he ran to the El Monte, took out the for sale sign and we have not seen the car again. I have pics and video of the El Monte.

 

2). Z-16 mysterious missing car. An NCOA member in Bloomington, IL had ordered a 1965 Z-16 396 Chevelle to replace an Impala he raced. It was delivered with all the Z-16 unique items, but when they popped the hood,it was a 327. He refused it and it was sold and he bought a 65 L-79 Nova. Then while Fran and I were walking around the showfield in Columbus, OH for the 1991 NCOA Convention, a fella from Detroit walks up and said "my shop just worked on an odd 1965 Chevelle". It was not a Z-16 but had a 396 and being the shop owner I know it wasn't swapped in. Fran's response was "what color was it and what model". Upon getting the answer he said "go find that car". He said that a GM executive had ordered the Z-16 goodies in a plain Chevelle and he got it. That combined with the Z-16 in Bloomington coming with a SBC, verified both accounts.

 

Interestingly, about 11 years ago we found the 1965 special ordered Z-16 equipped plain Chevelle. The GM exec died and his brother in TN got it. He then pulled all the Z-16 drivetrain, sold the drivetrain and installed Buick or Pontiac drivetrain in it. We know where the original Z-16 engine is.

 

Love stuff like this.

[7tonemonte]

Great stuff there I love reading things like that. Urban legend or not it always stirs up debate. You never know what car companies did back then and it makes total sense

[gprimm]

Yes, indeed. These are no urban legends. There are a few others he told us about. I find it fascinating that unlike Pontiac Historical Services, Chevy said they could not do it. What I learned from Fran is that the info was indeed available, and he had it.

 

Also, he would get the Corvette guys mad. Why? They thought their engines were built differently; nope. He would tell them the Tonawanda engines were built the same, put on crates and then shipped to the plants. St. Louis Vette plant had no special engines. Also, how you they get crazy on the "TR" marked bolts, well, he said that's nuts. They had one guy assigned at the plant to chase down needed hardware. They weren't going to shut down a production line because they ran out of 1/4 inch bolts for the valve covers so when the stock got low, they'd send the guy out and he'd have a 50 mile radius of hardware stores to go get whatever was needed.

 

Have lots more, but enough!!!

[714024SPEED]

I also read that plant workers went on strike for 67 days from sept. - mid nov. That caused GM to use some of the left over parts from 1970 on the 1971 model cars.

[Sam (Bones)]

in '70 corvettes got a 390hp 454, others got the 360hp 454, they are the exact same engine, they rated the horsepower at different RPM's

[LostnFound]

Hey Shawn....My SS has a production date of April 6th, 1971 and a shipping date of April 7th, 1971. The engine block is T0318CPD which is March 18, 1971. I'm not sure what the date of the heads are because I've never had them off. I suspect that your heads are correct to your block though as they are within a reasonable time line of each other. What is the production date of your car?