PatOpsahl

I am starting this over with all the information I got here and from others. Were any blocks with casting 3782870 put in vettes from the Tonawanda plant? I have heard that it is possible? If not, did the Tonawanda plant produce any 3782870's from 1962 to 1967? If yes, did they configure some to L76 - 365hp? My engine code is T0924HH.
were did Tonawanda plant put the block date code? I can honestly say there is no date code on the blocks right rear deck. Do I have 1966 heads with 2.02 intake?

Here is all of my numbers, maybe someone can tell me what my block is without me tearing it down.

I bought a 1965 corvette convertible with the seller telling me that it had a 1963 engine, 327/365hp and 4 speed trans. My investigation on the engine and trans numbers is documented below.

These are the numbers off the engine and transmission.
Casting number 3782870 found at the left rear of block. Below the casting number is 12363.


On the block right rear is the letters CONV 1, located on midway corner. No date code is visible, checked area from center top near the distributor opening and crankcase vent opening down to bottom edge of deck.


Right front on the block deck is T0924HH (stamped).



Right Head 3890462 / I286
Left Head 3890462 / I66
Bellhousing on right side 3858403
Transmission on right side 3851325, US Patent no 3088336, General Motors Corp.
Transmission on left side 3884685

Thanks again for any information you can give, also can someone explain the procedure to attach images here?
Patrick

Donald #31176

Pat,

There are no known Tonawonda SB blocks orignally installed in Corvettes. All Corvettes got their SBs from the Flint engine plant.

wombvette

Well Donald old boy, the fact is that there were Tonawanda blocks installed in some 64 and 65 Corvettes. We have known about these things for many years and I have seen several over the years. Pat, the casting date on your block is I2363 which translates to Sept 23, 63 and the assembly date was 9/ 24/ 63 the next day. It would have been used in an early 64 not a 63.

BarryK

I'm no expert by any means and don't try to say I am, but reading straight out of the NCRS book, any Tonawanda 3782870 blocks are NOT correct for any '65 Corvette application.

There were a VERY LIMITED number of Tonawanda blocks with a casting number 3858180 to appear in '65.

2000Hoo

Your heads are actually 1967 model year 300/350HP Heads, not 1966. If I'm not mistaken, they used the 461 head castings through the 1966 model year and then used the 462 casting in 1967. Not sure on valve size. 1.94 or 2.02?

BarryK

I believe that's correct. Head casting # 3890462 is referenced for the 1967 327/300 and 327/350 motors.

ctjackster

leaving asisde the "Tonowanda blocks in a midyear" debate, the claim that the engine was a "1963 327/365 hp engine" is nonsensical - the 327/365 hp reference appears to be a reference to L76, which in 1963 was, of course, 340 hp. (the 63 fuelie was good for 360 hp) AND the block pad for 1963 vette engines were RC, RD, RE, RF SC or SD. The "HH" came along in 65, it WAS an L76 pad stamp designation. (in 66 and 67 an HH indicated something else - a 300 hp 327).

when you say there is no date code on the right rear of the block - do you mean the passenger side when you say "right"? Not trying to be a smart @ss, just trying to help another C2 owner find the casting date of his block . . .

Now, some folks say that there were Tonowanda blocks in 65, but as I recall these were supposededly 3858180 blocks, not 3782870 blocks - or maybe I remeber the "story" wrong (yeah and then there was this time that they ran out of SB hoods and the plant workers, being resourceful guys, simply put BB hoods on the cars ).

I hear JohnZ coming, I'll let him clear this up 65 L76 tonowanda thing up. . .

BarryK

Ct is correct, i missed that in your revised post Pat.
In '63 there was NO 327/365hp motor

so far you from what I can establish, you have a '65 car that the seller told you had a '63 327/365 motor which didn't ever exist. The block so far is an unknown but it does have 1967 327 heads on it from either a 300hp or a 350hp motor.
Can you give us the intake mainfold casting # also?
The big question though on what this motor realy is would be knowing what are the innnards as this sounds like it was a "made" motor.
One thing to look at is whether or not it's really a solid lifter motor inside. In '63 the "L76" motor was 340 hp as CT mentioned but it was also a hydraulic motor. In '64 and '65 the "L76" went to a solid lifter configuration and jumped up to the 365hp.

jimdvan

From what I find the block is somewhat known, its a 62-67 327 corvette casting.

BarryK

opps, sorry, you are correct.
While I was typing my last post I was remembering another thread similar to this one that the poster had trouble identifying the block via the code.

Pat, I didn't mean to add more confusion to this.


Barry

PatOpsahl

I'll try to clarify some of the questions and ask some more.
My block has the casting number on the drivers side where it is suppose to be. As it sits in the car, looking down from the casting number on the deck I see I2363 - is this the date code? On the passenger side at the rear of the block, oppisite the casting number is CONV 1, nothing else is visible on this side? Shouldn't I see the date code over here? Did Tonawanda do date codes differently?
The engine stamp at the right front, 'HH' - Did Tonawanda build this to L76 specs? This is what puzzles me, I have a 3782870 from Tonawanda with 'HH'?
I have no more questions about the heads.
The intake is a Edelbrock with non factory Holley.

Thanks everyone, I might understand this pieced together engine soon!

Patrick

wombvette

Yes, let me clarify my statement. I mearly reacted to the blanket statement that there were no Tonawanda blocks used in Corvettes peroid. There were some, but they were as far as I know 180s and not 870s. I made no comment on whether Pats engine was a Corvette engine or not. Pat, As I said the number on the RH side is the date code. Tonawanda used two places for the year, thus I2363 is Sept. 23, `63.

buckyb

I have a `65 conv. with what appears to be a replacement "180" block. As mentioned earlier, all Flint block date codes are on the right rear(passenger side) with one character denoting the year. My Tonawanda block date code is on the left rear (drivers side) and uses two characters to denote year.Apparantly only"180"s were used in corvettes.

.

buckyb

I have a `65 conv. with what appears to be a replacement "180" block. As mentioned earlier, all Flint block date codes are on the right rear(passenger side) with one character denoting the year. My Tonawanda block date code is on the left rear (drivers side) and uses two characters to denote year.Apparantly only"180"s were used in corvettes.

.

JohnZ

The casting date format and pad stamp indicate a Tonawanda block - if there's no square-head pipe plug just above the timing cover at about 11 o'clock, that verifies it as a Tonawanda block. The 870 block was used in Corvettes from '62-'65, but only from Saginaw Foundry and Flint Engine, not from Tonawanda. The only usages of the "HH" suffix are for Corvette 327's and a '69 passenger car 350, but Tonawanda never built any small-block Corvette engines; they may have supplied a small number of raw 8180 block castings for a short time to Flint Engine for machining and assembly in '65, but no complete Corvette SB engines were ever produced at Tonawanda. In short, it's NOT a Corvette engine, and never was. Sounds like an (incorrect) re-stamp.

PatOpsahl

This block smells fishy? I have a Tonawanda block because:
The engine code stamp is T0924HH
The engine date code is on the blocks drivers side rear deck below the casting number.
The casting number is 3782870, from the feedback this is not possible - Tonawanda did not produce any 3782870's?
What's next guys? Should I quite worrying about it - no! It sounds like more investigation. Please lead me to the experts. We all know that GM's record keeping in those days was sub perfect. I know this engine is good by the way it drives and performs. Before I take it apart to find out what is inside I would like to really track down some information/history.

Thanks, Patrick

BarryK

Pat

we don't need to lead you to the experts, you have already heard from one of the best experts available and that is JohnZ!

PatOpsahl

No doubt, I believe that from the time I posted this to the forum. All of you and espescially JohnZ are the best! But, we are not completely finished here with this post. The block casting #, date code and engine code are not matching up to... I don't know?

Vetterodder

It's got my curiosity up also. An 870 Tonowanda block? Have the casting numbers been also faked???

BarryK

well, think about all the information you already have.
You know the casting # and date and that it's a Tonawanda block.
We know from JohnZ's posting alone that Tonawanda never built any SB motors for the corvette BUT you have a Tonawanda block.
We know from this that the motor in your car was NOT originally a Corvette motor and was installed at some point as a replacement motor and this motor came from a car or truck other than a Vette. Now, with the 3782870 casting # and date we know it's a '63 327 motor from Tonawanda but at this point not the application your motor was originally used for.
Chances are that's all the info we are ever going to be able to get out of this motor. It is a motor that probably could have been used and originally installed in any number of various models of cars in '63