alfons

Who is familiar with block casting numbers? What is the difference (also internal) between both engine block casting numbers. 3737739 is indicated for 58 and 'early' 59, 3756519 is listed for late 58 through 60. My car has VIN J59S100655, representing vehicle assembly date of appr. Nov-03-1958. Does it belong to the range of 'early' 59 or not? What is the right block casting number of the vehicle...? Please help! Al

monkfunk

I'm right there with you on this question. My 58 was built in april / may and I was told the 3756519 is correct but the last time I asked on this forum I was told I needed the more popular 3737739. My Vin number is J582107424. If you look on Rowley Corvette page http://rowleycorvette.com/stats58.html it shows the 739 as an early 58 and the 519 as later.
Don't forget that production of 58 started in Aug of 57, so don't confuse Later with November and December.
Mark

zadspal

For a car as early as yours I would most certainly go with a 739. The 519 blocks were "Late" 58 (the last month or so) and some early 59's had the possibility of a 739 block too. I would go with the 739 if you are planning on having the car judged. If you went with a 519 that would definitely raise a Question and you would need evidence to back up your use of that casting number. Play it safe and use a 739!
zadspal,

SunsetC6

Your cars could have had either casting number. The 739 block was used 1958 until early 59 which would have been somewhere in late Nov. early Dec. The 519 block was used from the middle of 58 until late 1961. So in theory the block numbers overlapped during the first quarter or so of the 1959 production run. I have a Dec. 59 car that has a 519 block in it and a friend has one about the same build time with a 739. Hope this helps.

Frankie the Fink

This site (1/2 way down page) shows 739 correct for early '59 car.http://www.corvette-world.com/corvet...ng-Numbers.php

alfons

Thank You all for the information provided! Any idea about the internal technical difference between the blocks. Think a different number may represent a different block construction for any improvement...?

71zman

Alfons,
One way to get this info is to ask other folks who have VIN #'s close to yours. If you look in the C1 Registry http://www.c1registry.com , you can find the emails of some folks who have similar production # cars with original motors - see if they will respond with block casting info..

bret

Frankie the Fink

Just looked through Noland Adams C1 Tech & Restoration Guide - the ultimate resource for such things. Although it discusses a wide range of head and intake manifold configuration changes for 58-60 there is nothing indicating the 739 and 519 blocks were any different. They are cited as having the same horsepower, etc. in the base configuration.

JohnZ

The 519 was the first block to use the new 2-piece neoprene rear main seal; all prior blocks were machined for the old "rope" seal.

Frankie the Fink

Hmmm...didn't see that in my reading; but I don't doubt it at all...not enough reason to keep me from using either block though.

alfons

Bret - as to Your suggestions: I got an info of an owner of a top flight car - one of the first 59 assembled in September 1958 with the 519 taken for correct. As this car was assembled some time prior to mine, I presume the 519 may be correct for me. Such is still present, but without matching casting date, and engine assembly stamping belongs to a passengers car. But - concerning all Your opinions - I think either block may be ok.

John - interesting to know about the sealing!

Found that info after looking around at Google:

3737739 - 170 (220? at another site) Low Power and 290 High Power
3756519 - 170 (230? at another site) Low Power and 315 High Power

were "High Power" is the maximum rate HP this block was used for, "Low Power" is the lowest rated horsepower RPO engine the block was used in.

Sometimes the 739 is said to be used for passenger cars only and the 519 also for trucks - sometimes said it is for both vehicles - really dazzling...

SunsetC6

[QUOTE=alfons;1564437282]Bret - as to Your suggestions: I got an info of an owner of a top flight car - one of the first 59 assembled in September 1958 with the 519 taken for correct. As this car was assembled some time prior to mine, I presume the 519 may be correct for me.

This is what I was referring to in the above post. The blocks overlapped in production and any one could have been intermixed in the assembly process. They pulled whichever was next in line and used it whatever the cast number was and eventually all that was left was 519's thereafter. They basically used what was available. As an example: I have a July 13, 1959 car that has never been touched until now (in a barn since 72) and the passenger door has the 59 door reveal mounting system and the drivers door has a 1960 style. This was late in the year and they used what they had as changes came about.

alfons

[QUOTE=SunsetC6;1564437860
This is what I was referring to in the above post. The blocks overlapped in production and any one could have been intermixed in the assembly process. They pulled what whichever was next in line and used it whatever the cast number was and eventually all that was left was 519's thereafter. They basically used what was available. As an example: I have a July 13, 1959 car that has never been touched until now (in a barn since 72) and the passenger door has the 59 door reveal mounting system and the drivers door has a 1960 style. This was late in the year and they used what they had as changes came about.[/QUOTE]

Mark - yes, your description may mirror what happened in those remote times, when the vehicles were treated as the next item on the assembly line, and the workers did not mind all concerns for accuracy of todays enthusiasts. Thank You! Al

SunsetC6

It is really amazing when start looking at some of the things they did back then. I have found many little things that are different on this car from the early 59 I have and it is really cool to research it. One door jamb striker did not have a shim behind it and the drivers door did and the same passenger side door light button had 2 gaskets behind it, the top spears on the fender had a screw in the back instead of the most rearward clip. This is something that was only done on the last 500 cars or so (It looked to be original but I did question this to comfirm it was true and it is). It is really neat discovering these little things here and there on the car. Believe me I have taken many pictures.....and will take alot more before it is done.

zadspal

I must correct myself. I didn't read the intire vin number in your original post. I only read the last digits. Your car is a 59, I thought you were doing a 58. I'm such a big dope! Now reverse my earlier post and you have your answer. Sorry for being such a dumb donkey!
zadspal,

alfons

Scott - don't worry! You should know that I'm sometimes more than scatterbrained (or is absentminded the right word. No, what counts is trying to help. I appreciate every single answer in this awesome internet forum!

DocsRocknRoll

Was the 3756519 casting code originally used in GM cars other than the 59 Corvette?

JohnZ

Yes. It was used in LOTS of other passenger car and truck applications.

DocsRocknRoll

JohnZ - Thanks for the response. I recently bought a 1932 Ford Roadster Hi-Boy. I knew the engine was GM. The seller told be it was a 350 motor from a '59 Corvette. I knew that was bogus and then researched the casting code number because the '59 wasn't built with a 350 motor.

Sorry to make the Corvette community cringe at the thought of a dearly beloved Corvette mortor being installed in a Ford hot rod. Believe me, I prefer to keep everything consistant too, either Ford all the way through or Corvette all the way. Maybe one day I will swap out the motor for a Ford 302, or whatever fits. The subject casting coded motor is a very fine rebuilt motor. If I make the swap I'll post it for sale on this site. Again JohnZ - Thank you.

jimgessner

A good friend just bought a 57 Corvette and in the garage there was a spare engine.

On a close look, it was dikscovered it was an early 519 block with a June 5, 1958 casting date and a F609CU assembly date, and was a 270hp original Corvette engine. It would be perfect for a vin number 7960 or there abouts. It may still be for sale. Note the rebuilder number on the pad