Need 1966 late production small block info.

[Jim C.]

About a month ago, I started a thread pertaining to the cylinder case casting numbers used during the production of late 1966 small block Corvettes. At some point during June/July, 1966, some small block (327/300 and 327/350) cars appear to have been manufactured with cylinder cases that had casting number 3892657, instead of the more common 3858174. Well, since posting that thread, several NCRS members have contacted me and suggested that I try and conduct some sort of survey on the topic. I thought about it and decided to give it shot.

In an effort to keep things focused, I've decided to narrow my search to only those 1966 small block Corvettes that fall between VINs 23000 and 27720. The cars falling between those VINs basically cover the production months of June and July, 1966. If you have one of these 1966 Corvettes here are the questions you could answer for me:

1. Do you believe the block in your Corvette is original to your car? (A brief statement as to why you think it's original, or not original, would be very helpful.)

2. Has the block's stamp pad been altered in any way?

3. Are the trim and VIN tags located beneath the glove compartment original to your car?

4. Looking at the trim tag, can you tell me the date your Corvette was made? Is it an AO Smith body or STL body? (For example, mine reads "K28" and "S8886")

5. Looking at the VIN tag, what is your Corvette's complete VIN? (Mine reads "194676S127592")

6. Looking at the block's stamp pad, can you tell me the assembly date code? (Mine reads "F0726HE")

7. Looking at the rear of the block, on top of the driver's side bell housing flange, what casting number do you see, 3858174 or 3892657? (Mine reads "3892657")

8. Looking at the opposite rear side of the block, on top of the passenger side bell housing flange, what casting date code do you see? (Mine reads "G116")

That's it. If you own a 1966 small block, late production Corvette, between VINs 23000 and 27720, and feel like contributing to my research, I'd REALLY appreciate your efforts. If I get enough responses, I'd like to write an article for a future issue of the Restorer magazine.

Please send your responses to: jlcicchini@aol.com

Thanks again for any help/info you can provide.

Jim C.

[Jim C.]

Re: Need 1966 late production small block info.

Wow!! Not even one response!?!?!?!? I'm surprised.

[Gary B.]

Need 1966 late production small block info.

Jim,

Just a thought. Some people may be concerned about given out their complete VIN number. Isn't the build date enough for your survey? Also, you should consider putting a notice in the Corvette Restorer and/or Driveline. A minority of NCRS member may actually use the DB.

Gary

[Jim C.]

Re: Need 1966 late production small block info.

Gary,

I was thinking about the whole VIN security issue prior to even taking on this project, but then considered the fact that these Corvette VINs are posted all over the internet and in publications to include the C2 Registry (which actually publishes which state the car is in), the 1963 -1967 Stingray Registry, Ebay, and in various sections of the Driveline. As a matter of fact, prior to posting an ad (for sale, info wanted, etc.) in the Driveline I think one has to provide the car's VIN.

My survey does not ask for the car's location, or any specific information about its current or prior owner(s). If I did discover any of that information during my research, I certainly wouldn't share it with anyone. I do ask for the build date, but the VIN tells me specifically which cars got the 3892657 blocks and which ones didn't. I've already received about 25 responses (from other sources than the NCRS Tech Board) and found two cars that were built 10 units apart. One car has the 3892657 block while the other has the more common 3858174 block. I wonder why?? Both had the same build date.

Obviously I haven't physically inspected any of these cars, and even if I had, who am I to say what's original or not? I'll leave that to the experts. I'm just trying to identify specific cars that have the 657 block. The point is that cars from the same build date may have received one block or the other. It's interesting to see which ones got the 657 block and which ones didn't, particularly if they were close together coming down the assembly line.

I still need many, many more examples if I'm going to ever make heads or tails out of any of this. Just from the few responses that I've received so far from other sources, I've learned a lot, and can say that there is some evidence that 657 blocks were being installed in late production 1966 Corvettes.

I do plan to put an ad in the Driveline and/or the Restorer. Hopefully I'll get more responses. I thought/hoped the Tech Board was also a good place to look for respondents. Maybe not. I can say that any time I've seen other members looking for "numbers" (including my VIN), I've provided them if I thought such numbers were pertinent to the conversation. As a matter of fact, I reference all my Corvette's numbers in my own survey. Finally, I have received a few surveys with missing information, and some haven't responded at all. Clearly, people decide what, if any, information they wish to provide.

I'm just a little surprised to see that I've received zero responses from the Tech Board. Maybe this wasn't the best place to go looking for the information.

Jim C.

[Paul J.]

Re: Need 1966 late production small block info.

Jim,

I assume that you've aggressively gone after those listed in the C2 Registry.

Another thought is to ask someone like John Hinckley if they know someone who would have been at the engine assembly (or casting) plant at that time and try to contact them, or perhaps run an ad in thier local paper.

You may have already thought of this.

Paul

P.S. I've never understood this paranoia about making VINs public. If I was going to steal a VIN the very last one that I want is one that's been made public, one that many people have seen.

[Gary B.]

Need 1966 late production small block info.

Paul,

I agree with what you say, but whether the VIN paranoia is justified or not, there are definitely people who will not publicize their VIN. And if the VIN is not essential to a survey, why ask for it? For the survey, the objective is to get responders.

Gary

[Paul J.]

Re: Need 1966 late production small block info.

I agree.....

[John H.]

Re: Need 1966 late production small block info.

Jim -

I did a survey on an apparent '67 intake manifold casting date anomaly about eight years ago, and started it on the TDB; got some input, but there were even fewer members using the TDB back then than there are now. I asked Eric and Gary to put it in the "Driveline" for me, and got LOTS of input, and subsequently reported the results in the "Restorer", and the anomaly was then recognized in the '67 Judging Guide. Put it in the "Driveline" - far more members will see it.

On the specific issue of the 174 vs. 657 block in late '66 cars, member Mark Gorney may be able to help you; Mark has been at the Saginaw Foundry (now called GM Metal Casting Operations) for over 30 years, and the intake manifold information he dug up from old foundry records on my '67 intake survey broke the issue wide open and provided the solid data for the survey conclusions. E-mail me for his contact information or use the "Members List" item near the top of the page to contact him.

[Jim C.]

Re: Need 1966 late production small block info.

Paul and Gary,

Thanks for the input on the whole VIN situation. I don't get it, but I guess there are some out there who see it as an issue. To be honest, even though I've only received 25 responses so far, ALL have provided their VINs without question. Now granted, I contacted those owners based on information that initially included their VINs (like the Driveline ads). Since I'm only looking at VINs 23000 to 27720, knowing the VINS going in saves me time by not contacting owners with VINs outside the target group.

Again, If owners don't want to provide their VINs, or any other data, then they won't and don't have to. I'd like to know specifically which cars got the 657 blocks and which ones did not. It's probably not critical that I know that, but it's of interest to me to see how cars so close together on the assembly line received one block or the other. From the very little that I know, both blocks were being used right up to the end of production, in some cases, on the same day. It's not like the factory used all 174 blocks one day and then switched over to the 657 blocks the next day. There was no cut off of the common 174 blocks and no distinct beginning for the less common 657 blocks.

I guess if you really boil it all down, I don't really need anything but the block's casting number. Is it 3858174, or 3892657? I still like seeing and comparing all the numbers. One thing that the VIN does do for me is it allows me to check cars off the list. If I know the VIN, then I know whether or not I've included the car in the survey. It acts as a control number for each response.

Jim C.

[Ronald L.]

Re: Need 1966 late production small block info.

Jim,

You know I'm in full support of what you are trying to do and all I can say is follow John's advice and get with the casting guys at GM, first, and second, statistics rule, there are 100+ max 189 users of the disc board and its a guess how they are split for C1 C2 C3 and up, maybe 30 people over 5 years of c2 so you got what you got from the board and if you had 5 responses - you got everyone with C2 & 1966.

Point is with over 15000 NCRS members the driveline should get a good response, the deadline passed for the July Aug issue but you can get one in for September and at this rate have it fine tuned. Good luck, if you need help looking at or organizing the data let me know.

[Jim C.]

Re: Need 1966 late production small block info.

Ron,

I'm writing something up now to submit to the Driveline. I think it will help. The more exposure the better. Like I said earlier, if I get enough responses, I'll put something together for a future Restorer article. I need to get the information first. I'll keep you posted.

Jim C.

[Paul J.]

Re: Need 1966 late production small block info.

Jim, I had another idea. The "for sale" web sites sometimes list the VIN (24713, 23929, 24303, and some others are on Usedcorvettesforsale.com right now). They should also provide you the VIN of those not listed. Asking the VIN and block casting number is a routine purchasing exercise. There are many sales and dealer sites.

I know that this won't give you all of the information that you're looking for, such as the originality of the block, but it might provide some useful information.

Paul

[Jim C.]

Re: Need 1966 late production small block info.

Thanks Paul. I'll check it out. The more examples I can find the better.


Jim C.

[Ronald L.]

Re: Need 1966 late production small block info.

Here is one of these cars with a block that's not supposed to be?

http://cgi.ebay.com/ebaymotors/1966-Chevrolet-Corvette-Coupe-Match-Very-Original-/110566533303

Anyone verified this cars originality?

[Jim C.]

Re: Need 1966 late production small block info.

Hey Ron,

I saw that one on Ebay too, but thanks for making sure I didn't miss it. I'm trying to find out a little bit more about the car, and will hopefully add it to my list of 657 blocks. I've found a few others too. It's a VERY late car, right there in the time frame that seems to have produced cars with the 657 block. I'll keep you posted.

Jim C.