66 Big Block Engine Casting Number

[Jeffrey C.]

Hello all. New to forum and excited to be here. I do have a question about my newly acquired 66 427. From my handy dandy NCRS Technical Manual and Judging guide, I look to have the correct casting number of 3869942 for a 427. In addition, my assembly stamping is correct at T0329IP (Tonawanda March 39 and IP for 66 L72 427 with 4spd) and my VIN stamp on the engine matches the VIN. HOWEVER, the Casting date on the bottom of the engine is C108 which is March 10 1968. I double checked because 6's and 8's can look a lot alike in a cast, but it's definitely an 8. So here's the question, how can that be? How can the numbers on top of the block be matching for a 66 big block and the numbers on the bottom of the block point towards a 68 427? Any help would be appreciated. Thanks much.

[Keith B.]

Re: 66 Big Block Engine Casting Number

942 blocks were only cast and made for the 66 model year 427 engines.

[Joe R.]

Re: 66 Big Block Engine Casting Number

Well after looking at the casting date with the proper magnification you will find that the "8" is actually a "6".

And don't argue with me if you want to get it judged. Hint Hint!

JR

[Joe R.]

Re: 66 Big Block Engine Casting Number

Hi Jeffrey,

Welcome to the club!!! How about a picture of the casting date?

Joe

[Joe L.]

Re: 66 Big Block Engine Casting Number

Hello all. New to forum and excited to be here. I do have a question about my newly acquired 66 427. From my handy dandy NCRS Technical Manual and Judging guide, I look to have the correct casting number of 3869942 for a 427. In addition, my assembly stamping is correct at T0329IP (Tonawanda March 39 and IP for 66 L72 427 with 4spd) and my VIN stamp on the engine matches the VIN. HOWEVER, the Casting date on the bottom of the engine is C108 which is March 10 1968. I double checked because 6's and 8's can look a lot alike in a cast, but it's definitely an 8. So here's the question, how can that be? How can the numbers on top of the block be matching for a 66 big block and the numbers on the bottom of the block point towards a 68 427? Any help would be appreciated. Thanks much.

Jeff------


No matter how much the last digit might look like an "8", it's a "6". Guaranteed.

[Jeffrey C.]

Re: 66 Big Block Engine Casting Number

Thanks for the quick responses. The cynic in me worries about altered VINs. Here is a picture of the casting

[Mike M.]

Re: 66 Big Block Engine Casting Number

the embossments that occur when casting dates are cast into sbc and bbcs are notoriously difficult to read. i believe what we are looking at is in all likelihood a 6 that the casting process got a little sloppy . mike

[Gary J.]

Re: 66 Big Block Engine Casting Number

Agree with Mike, mine is hard to read too

[Jeffrey C.]

Re: 66 Big Block Engine Casting Number

Thanks guys for all of your help

[Joe L.]

Re: 66 Big Block Engine Casting Number

Thanks guys for all of your help

Jeff------

This situation reminds me of the 1968-76 power brake master cylinder casting number. Many folks swear that the casting number is 5480346. I have to admit that the third digit does look like an "8". However, I have long-ago confirmed that no casting of any kind was ever released in the series 548xxxx.