1964 C2 Motor Authentication

[Michael W.]

I'm Mike Webster. I own a '64 C2 and have been unable to authenticate my motor.

Data:
VIN# 401867S110314 Final assembly early February 64
Engine Pad: 4110314 F0104RC Jan 4, 1964
Cast# 3782870
Cast Date Code: L1663 Dec 16, 1963
327/250
3-sp Saginaw Transmission

Engine stamp pad and casting identification markings appear unaltered. The motor has the square plug forward of the intake manifold verifying it is a Flint machined/assembled block. I'm the third registered owner of a 66k mile car.

The judging manual says all C2 motors were cast in Saginaw, machined/assembled in Flint. The only rare exception are those blocks cast in Tonawanda with a casting #3858180, all being machined/assembled in Flint. My 3782870 block was cast in Tonawanda, machined/assembled in Flint.

I contacted Al Greening, he was unable to authenticate my motor because there are no other examples in his database. I am curious if any member owns or knows of a '64 C2 built approximately the same time as mine with a 3782870 Tonawanda cast block. I'm looking at a vin sequence around 10,000-10,500.

Appreciate any help in this matter. Thank you.

[Mark F.]

Re: 1964 C2 Motor Authentication

I'm Mike Webster. I own a '64 C2 and have been unable to authenticate my motor.

Data:
VIN# 401867S110314 Final assembly early February 64
Engine Pad: 4110314 F0104RC Jan 4, 1964
Cast# 3782870
Cast Date Code: L1663 Dec 16, 1963
327/250
3-sp Saginaw Transmission

Engine stamp pad and casting identification markings appear unaltered. The motor has the square plug forward of the intake manifold verifying it is a Flint machined/assembled block. I'm the third registered owner of a 66k mile car.

The judging manual says all C2 motors were cast in Saginaw, machined/assembled in Flint. The only rare exception are those blocks cast in Tonawanda with a casting #3858180, all being machined/assembled in Flint. My 3782870 block was cast in Tonawanda, machined/assembled in Flint.

I contacted Al Greening, he was unable to authenticate my motor because there are no other examples in his database. I am curious if any member owns or knows of a '64 C2 built approximately the same time as mine with a 3782870 Tonawanda cast block. I'm looking at a vin sequence around 10,000-10,500.

Appreciate any help in this matter. Thank you.

Hi Mike,

Welcome to the TDB...

Post some hi quality photographs to this post so those in the know (or have one close to yours) can try to help...

If you have already contacted Al, and he has no data...you must really have a rare bird, indeed!

Good luck!

[Michael W.]

Re: 1964 C2 Motor Authentication

Thankyou. I uploaded requested photographs.

[Bob R.]

[James W.]

Re: 1964 C2 Motor Authentication

Mine engine was built 10 days after yours. F0114RD. Casting date A124, VIN 4109258. Yes, two (2) days prior to assembly. My car has been judged at all NCRS levels and scored Top Flights at all levels.

James

[Richard M.]

Re: 1964 C2 Motor Authentication

I always thought the cast date was on the opposite side of the bellhousing flange just below and to the right of the distributor.

Michael, is there a cast date at that location also?

Did all Tonawanda blocks have their cast date at this location as shown below?




Edit, What's also unusual, is that the casting part# is in the opposite direction, not inline with the "GM" cast orientation. i.e. the 870 is pointing out, not in.

File photo - Tonawanda 1964 block. Font is much smaller than above and opposite placement, 870 pointing inward. Also note cast date not like above. It's on the Pass side.
47636873d1239375362-1964-corvette-engine-tonawanda870.jpg

47636874d1239375362-1964-corvette-engine-tonawandadate.jpg

[Michael W.]

Re: 1964 C2 Motor Authentication

From December 20, 2012 thread.........

We see this on occasion in 1969 to 1972 Corvettes, and I recall one case in 1973 to 1977. It does not surprise me that there are other cases. The folks at Flint Engine told me that "from time to time a batch of Tonawanda cast cylinder cases" would be sent to Flint for machining and assembly. The purpose was to ensure that the Tonawanda cast cylinder cases would fit the tooling and machines at Flint so that an alternate casting site was available should Saginaw Metal Casting be unable to supply raw cylinder cases or could not meet sufficient demand for cylinder cases to Flint Engine.

.......

My Stamp Pad identifies my motor was built on Saturday January 4, 1964. It's possible Flint Engineering ordered up some Tonawanda castings to be run through the machining lines to identify any glitches in machining in the event Saginaw was unable to support Flint. If that's the case, I should be looking for motors built with a few days of New Years 1964. Difficult indeed......

[Gary C.]

Re: 1964 C2 Motor Authentication

Guys,

AFAIK only Flint C1/C2 small block engine blocks had the 1/4 inch tapped/plugged hole on the passenger above the water pump?

Gary
....

[Michael W.]

Re: 1964 C2 Motor Authentication

I am not positive, but I'm sure there were multiple sets of Foundry Pattern Equipment utilized in order to support production. Location & size of part numbers could have at the discretion of the patternmaker. As far as I know, the date code showing the two digits for the year is the most indicator of a Tonawanda vs Flint block.

[Gary C.]

Re: 1964 C2 Motor Authentication

Michael,

C1 & C2 Flint blocks had 2 things different from Tonawanda machined blocks:
1) the 1/4 inch plugged oil hole
Flint Block Front Oil Plug w-Arrow.jpg

2) Left Rear Non-milled area
Flint Block Non-Milled Area-crop.jpg

Saw the plug in your photos.

Question - is the area in #2 milled or not?

Gary
....

[Terry M.]

Re: 1964 C2 Motor Authentication

Guys,

AFAIK only Flint C1/C2 small block engine blocks had the 1/4 inch tapped/plugged hole on the passenger above the water pump?

Gary
....

That is correct Gary. Those Tonawanda cast cylinder cases that were sent to Flint for machining and assembly had that tapped and plugged hole in spite of their Tonawanda cast beginnings. The machining operation and location dictated that feature.

[Gary C.]

Re: 1964 C2 Motor Authentication

Terry,

There was proof of some 1965 small blocks castings sent from Tonawanda to Flint. But, that's the only documented instance for C2.

Gary
....

[Terry M.]

Re: 1964 C2 Motor Authentication

Terry,

There was proof of some 1965 small blocks castings sent from Tonawanda to Flint. But, that's the only documented instance for C2.

Gary
....

I was trying to stay away from commenting on the C2 situation directly lest I encounter the ire of #14 again. I only wanted to point out what we have seen in the early C3 cars. If one chooses to stretch that information into C2s, one does so at their own risk.

[Joseph S.]

Re: 1964 C2 Motor Authentication

To my knowledge, ALL 63-64 Corvette blocks have the large font 870 casting number and the casting date on the opposite side of the block. All casting dates have only the 2, 3 or 4 for the year. Blocks with a 62, 63 or 64 casting year are Passenger car blocks. IF, and I repeat IF, someone did not know this and grabbed a passenger car block to deck and stamp, this would be the result.

[Patrick B.]

Re: 1964 C2 Motor Authentication

If I understand this issue correctly, we have a Tonawanda 870 block that has some characteristics of having been machined in Flint. No one has ever heard of or seen previous Tonawanda castings machined in Flint in 1963 (1964 model year), but there were documented examples of this practice in a known time period in 1965. Gary offered pictures in this thread of machining differences between Flint and Tonawanda. Flint blocks had a plugged hole near the timing chain cover that Tonawanda blocks did not. Tonawanda blocks apparently had a milled area near the bell housing that was not milled on Flint blocks. Joe presents the scenario of someone restamping this block in ignorance that Tonawanda blocks were not used for 64 Corvettes.

I think we still have a mystery. Why does this block have a Flint-only plug near the timing chain cover? If someone was trying to doctor this block to look Flint-like that is certainly not a sign of ignorance. Michael, the original poster, will you post a picture of the rear surface that Gary identified as machined in a Tonawanda machined block. That is a sign that probably can't be doctored.

This block is peculiar. The casting number is upside-down and the casting date is in a odd place. The stamping has no obvious disqualifying features. I hope Michael will provide a picture of the rear driver's side area. However, if someone has another example of a 250 hp, manual trans engine pad stamped on January 4, we will know where this engine was stamped. There were at least 3 different styles of F, 0 and R in use in 1964. If these variations fall in the same locations between a ordinary Flint block and this oddball block, I would say it was probably machined at Flint even if that makes it a unicorn.