engine code and vin

[John T.]

Hi I own a 1956 corvette, mid august production. power glide .past duntov winner. Anyone with info on the block #? Info i've looked up doesn't show this number sequence. Thank you, John

[Garry B.]

Re: engine code and vin

John, here's what is known and what isn't. The first series of numbers are the production numbers of the block. If you notice closely, the first five numbers are perfectly aligned with each other. They were placed in a "gang" stamp and stamped with a single blow. The next two digits (a zero and a 1) were stamped separately to complete this production number. These last two digits are always misaligned with the previous five because of their individual stamping. The F indicates that the block was produced in Flint, MI which is where the corvette blocks were cast. The 56 indicates the year and the FG is the suffix for a 265 cubic inch, dual quad, powerglide corvette. You mentioned that your car is an August car (late) so the larger production run number correlates with the later assembly date of your car. The other important numbers are the casting number on the drivers side down near the bell housing and the casting date which can be found on top/center of the block next to the distributor. It can be hard to get at without a mirror, but you can find it. In essence, the production number has no direct correlation with your VIN with the exception of it indicating that there is an alignment with the later VIN and the production of the block. I will that this assumption isn't always the case, because if a block was pulled from the assembly line for repairs and once repaired put back into line, it might appear a bit off as compared to the assembly date of the car. If it's a prior Duntov car, you should have no concerns about authenticity.

[John T.]

Re: engine code and vin

Thank you very much for the info!!!!

[Garry B.]

Re: engine code and vin

John, I edited my response just a bit to include more information about the production number. Please re-read. Anything else you have question about? I can say that your stamp looks very original including the broach marks. I have looked at a lot of '56-'57s and yours is spot on.

[Edward M.]

Re: engine code and vin

I concur with Garry, looks like a solid stamp to me.

Also, as a bit of additional info, there is a ROUGH correlation between VIN and engine sequence in that both increase as a function of date.

1956 #4358 (E56S004358) has an engine sequence number of 059I975.

Your car #4026 is 332 cars prior to #4358. Your engine sequence of 054990I is 42074 engines (all engines, not just Corvette engines) earlier that the engine in 4358.

That delta makes good sense to me.

I think you are fine.

[Eric T.]

Re: engine code and vin

Hello I'm a new member but was a member back in the early 1980's. I wrote several articles for the drivetrain back in those days.

I have owned a 56 Corvette for 30 or more years. Unfortunately my life got far too busy fighting forest fires and doing a lot of other stuff. So I put my TriFives including my 56 Corvette in a barn on my brothers ranch in Ontario, Oregon.

Well I'm now semi retired and have completed a couple of restorations on some newer cars and trucks. I'm getting excited about starting to do the rolling frame on my corvette which I've owned since the 70's.

My corvette vin is E56S03011 #2011 Best of my research is that this car was built about 6/28/1956 It was the 2 x 4bbl powerglide car. I have a block Cast 3720991 Stamp 0515150F56FB cast date E286 (5/28/56)

I have most of the parts to finish the car including all of the drive train some that are not exactly the correct date but the right part#s.

The issue I have is that there has been a block on ebay that could be the correct stamp and cast date for my car. It is 3720991 Stamp 0517451F56FG cast date F46 (6/4/56). Attached is a picture of the block serial# stamp. I have other pictures as well but this is my main concern.

I'm thinking if I got this block I could put the drive train together with all the correct parts (part#s and dates) that are difficult to replace. The parts with the wrong dates or part#s are exhaust manifolds, distributor, generator, starter and the like.

My main concern is that I'm not sure this is not a restamped block. Can anyone help me determine if this looks like an original corvette block?

Thanks

Eric D. Twombly New member #5888 I'll see if I can find my old member # or is it possible this is my old member #?

[Don H.]

Re: engine code and vin

Eric
looks like they resurrected your old number. Your profile says you joined in August 1982. Welcome back. We missed you.

[Edward M.]

Re: engine code and vin

ERic;

I personally would question this block. As indicated earlier in this thread, the stamping sequence for 1956 Corvette engine was 5 - 1 - 1 - 5
First 5 characters of sequence number stamped together in a gang holder, then the last two characters of the sequence numbers stamped individually, then the engine code characters stamped together in a gang holder.

Clearly the last character in this stamp 'G' was stamped individually. I believe the original code for this engine was F56F (2bbl, powerglide, in a passenger car) and someone added the "G" after the fact.

[Edward M.]

Re: engine code and vin

Here is some data related to 1956 VIN and engine sequence numbers that I have gathered over the years...

E56S001041	0217257	F56GR
E56S001045	0033225	F56FG
E56S001109	0115112	F56FG
E56S001150	0183115	F56FG
E56S001200	0253394	F56FG
E56S001241	0200520	F56GR
E56S001277	0310849	F56FG
E56S001279	0214931	F56FG
E56S001316	0313883	F56GR
E56S001331	0342299	F56FG
E56S001332	0308661	F56GR
E56S001373	0325102	F56FG
E56S001407	0318266	F56FG
E56S001417	0325244	F56FG
E56S001461	0342299	F56FG
E56S001479	0342239	F56FG
E56S001490	0332616	F56FG
E56S001491	0332265	F56FG
E56S001544	0353654	F56FG
E56S001545	0336982	F56GR
E56S001585	0357170	F56FG
E56S001658	0356276	F56FG
E56S001707	0377104	F56FG
E56S001780	0271753	F56GR
E56S001792	0389269	F56FG
E56S001797	0378312	F56FG
E56S001827	0391058	F56FG
E56S001839	0400863	F56GR
E56S001865	0207957	F56FG
E56S001939	0402424	F56FG
E56S001940	0387927	F56FG
E56S001964	0401495	F56FG
E56S001972	0389269	F56FG
E56S002002	0421175	F56GR
????	0447249	F56FG
E56S002274	0450825	F56FG
E56S002279	0453647	F56GR
E56S002550	0471532	F56FG
E56S002609	0620340	F56FG
E56S002775	0499829	F56GR
E56S002842	0506800	F56FG
E56S003283	0336661	F56FG
????	0533929	F56GR
	0552829	F56FK
E56S003566	0571297	F56GV
E56S003584	0575748	F56GR
E56S003714	0586863	F56GU
E56S003949	0614187	F56GR
E56S003961	0614249	F56GR
E56S004026	0549901	F56FG
E56S004358	059I975	F56FK
E56S004126	0600392	F56GU
E56S004200	0650477	F56FG
E56S004434	0591850	F56FK
????	0666123	F56GU
E56S004444	0669936	F56GV

[Garry B.]

Re: engine code and vin

Eric, I would have to agree with Ed's assessment of the block you are looking at. The numeric characters look fine with the exception of two. The 4 is a little different than mine, which there may have been a few different stamps used, but the G is clearly stamped later and is just a bit different than mine. The cross section is a bit shorter on the one you are looking at. That too may be explained away, but you can't explain away the positioning of the G which has been added later. Keep us posted on your progress and feel free to reach out. There are a lot of very well informed "56 lovers on here.

[Eric T.]

Re: engine code and vin

Thanks for the response. Your replies along with correspondence with John St Peter. Confirmed my doubts.

I'll continue to look for a block and work on some other projects for a while. If I can't find a correct one I'll put the FB block in the car and do a good restoration or something of the sort. I'll of course continue to consult with folks in NCRS as I move forward.

The advent of eBay and other internet sources make it easier to search. Historically I bought many of my parts once found on Vet Views or other sources and collected from other TriFive parts that were correct for the Corvette.

I plan to attend some NCRS events this coming year and get reengaged.

Thanks

[Edward M.]

Re: engine code and vin

Finding 2 bbl, powerglide, passenger car blocks is pretty easy.

Adding a letter to the end of the engine stamp to make it a Corvette engine is also fairly easy.

Making the additional letter undetectable is where the challenge comes in, but it really is not rocket science.

Also, E56S003011 has an "estimated" build date of 6/16/56. But, we all know that 56 production dates are just guesses anyway.

[Eric T.]

Re: engine code and vin

So how is that considered these days for NCRS judging.

I remember when I was more active it was considered OK but people were encouraged to document the engine as restamped and show that when the car is judged?

Thanks

[Edward M.]

Re: engine code and vin

So how is that considered these days for NCRS judging.

I remember when I was more active it was considered OK but people were encouraged to document the engine as restamped and show that when the car is judged?

Thanks

I don't know for sure, but remember the phrase "restoration engine".

My opinion is that if it is not detectible, it passes judging.

ON a related note, here is something interesting....

A 1956 engine, with machine work done, listed on Ebay.

Link:

https://www.ebay.com/itm/265-Small-Block-V8-Engine-From-1956-Chevy/253202188246?hash=item3af406c7d6:g:uYYAAOSwf3BZ1DcH&vxp=mtr

The "interesting" part is the pad stamp - 0592472 F56G.

Does not list the date code, but with a sequence number of 592 thousand plus, I am guessing it falls somewhere around June-July of 56 time frame. Also not that this is a manual transmission engine code

And here is another one on Ebay, with this indo on the pad:

Engine casting # 3720991 Block # 0382528F56G

Link: https://www.ebay.com/itm/CHEVROLET-265-030-SMALL-BLOCK-1956/291561923770?hash=item43e271e4ba:g:heUAAOSwgNRV8v-W&vxp=mtr

[Gary C.]

Re: engine code and vin

Eric,

Did I see a "T" in the stamp pad in front of the F. If so, the "T" shouldn't be there.

Did you get a photo of the block cast date?

This is a "real" '56 engine pad. Which was restored by my late friend Gilbert Scrivner.


Gary
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