Trophyblue66

I have to look at a 61 later today and I can't remember, which casting # size is correct, the large font 539 or small font 539? I think small font is original for a corvette, but I am not positive. Thanks!

Donald #31176

The original casting # for 61 is #3756519 or if very late #3789935. The Saginaw casting, correct for Corvette on the casting date the year is a single digit. Not sure of the font size of the casting # for 283s but for 327s the font is larger on Saginaw castings.

Trophyblue66

My memory is really foggy, got the casting # wrong. In any case, they had two different fonts for the #, I believe one was used in non corvette applications and the other was used in Corvettes.

john neas

I would think that the fonts size at Flint would be the same for all blocks made in the same time period.
Regards

C1Corvette

Casting numbers are 5/8" high for the correct Flint blocks, correct for the corvette as opposed to the Tonawanda blocks that had the 9/16" high numbers. The other way to determine the Flint blocks from the Tonawanda blocks is the Flint blocks had the one digit year designation as opposed to the Tonawanda blocks that had the two digit year designation. The 519 Flint block is correct as well as the 935 block from approx serial # 9,500 to the model end June-July. The Tonawanda 519 blocks are not a correct corvette application

Frankie the Fink

My original '61 is VERY late - like 100 cars from the end of production and has the 519 block...

C1Corvette

Sorry, just to clarify the 935 block may have been randomly used at the end of production. The 519 block was used throughout the entire year in 61

Trophyblue66

Thanks C1 that's what I was looking for.

JohnZ

Nope. Neither the Saginaw Foundry nor the Machining Department at Flint V-8 had the slightest clue what the final application was for any block; they were all the same until they went down the engine assembly line and got internals and externals.