help on engine numbers

[Mark U.]

i have a 427 390 hp 1967 vert-here are the engine numbers
block-3904351
heads-3964290-3931063-1 head was replaced by the factory under warr work
intake 3963569

i beleive the intake is not correct and should i try to replace one of the heads or is it right to have a replacement head on this car? I am trying to keep it as original as i can.

Thanks Mark

[Tom H.]

Re: help on engine numbers

Hi Mark ! I think your heads should be cast 3904390. Intake, 3866948 or possibly 3883948 depending on the production date.

I'm sure someone will chime in with more detailed information.

[John C.]

Re: help on engine numbers

Mark

Your block should be casting 3904351 like you have.

There are 4 possible heads used on a 67 390hp car. They are-
3872702 - very early cars
3904390 - through Dec 66
3909802 - Jan 67 to near end of production
3917215 - very late cars

There is a head casting 3964290 but it was used for the 1969 model year. Check your head number again as they are very easy to misread.

Your replacement 3931063 head was also used for 1969 cars. They will be minor accessory mounting pad difference between the correct 67 heads and this one but I doubt anyone would notice.

The correct intake manifold should be either casting 3866948 or 3883948.

Bubba has been at work on your current intake manifold. 3963569 is for a 1970 and 71 LS6. This manifold is meant for square port heads and not the oval that you have. It is also a low rise manifold and not the high rise style used in 67. What do you currently have for a carburetor on this?

John

[Mark U.]

Re: help on engine numbers

guess i need some numbers for heads and intake numbers..

Thanks Mark