Were very early 3963512 cast 427's used in 69's

[Jacob A.]

Hi I have a 3963512 block for sale locally. A potential buyer has told me that an NCRS judge told her that very early production 3963512 blocks such as mine,(I believe the date is J-10-8,) weren't installed in Corvettes at all.

According to the Black Book this casting # 3963512 was used in 69 Corvettes. If block casting date proceeds the build date of the car by 6 months or less... it is acceptable for judging.

So what would the actual story be?

thanks,
Jacob
# 40987

[Dick W.]

Re: Were very early 3963512 cast 427's used in 69'

512 blocks started showing up in the 2nd or 3rd week of December '68.

[Jacob A.]

Re: Were very early 3963512 cast 427's used in 69'

Thanks Dick,

Do you mean that a 69 Corvette with a build date the 2nd or 3rd week of December '68 or later could very well have had this 3963512 block dated Oct 10 68?

Thanks,
Jacob
#40987

[Dick W.]

Re: Were very early 3963512 cast 427's used in 69'

2 bolt usage started in Oct '68 and 4 bolt started in late October '68

[Mark #28455]

The block castings overlap

I personally own a 435 HP engine from approx car #6700 that is a 439 block cast F 8 and machined 10 31 68. The blocks were not selected in date code order for assembly. They were cast in order - 439 first, then 270 then 512. The first 439 blocks had cast clearances for the cranks that were too small for a 454 with 7/16" rods. Around May or June 68, I believe the blocks were machined for more clearance. The 270 blocks had this clearance cast in as did the 512 blocks. So, your block could have been used in a Corvette.

Mark