Mystery heads

[Curt R.]

I have a '59 that I am getting ready to restore and have very early VIN #100036and the engine has heads dated E-2-8 and F-29-8, they have X 8 marks on the side and smooth head marks on the ends which from what I have read, is unique to the Corvette heads, however there are three mounting holes which I have read are for passenger cars, also it appears that the two lower holes had a bolt screwed in and shaved off, could this be a factory thing? Has anyone seen these heads on a corvette ?

[Domenic T.]

Re: Mystery heads

Curt, you will need pictures.
I think those heads would be for a early 59, or very late 58.

Dom

[Curt R.]

Re: Mystery heads

Side shot.jpgHead Casting.jpgHead casting marks.jpgHead date code.jpg

[Leif A.]

Re: Mystery heads

Curt,
Look for casting numbers 520 or 896 on the heads where I have 462 in the pictures below. I believe what you have by the marking on the side of the head are

[Curt R.]

Re: Mystery heads

Thanks for the quick response, Gentlemen! I will check those casting numbers when I get a chance, the car is 36th off the line and has one of the leftover 3737739 blocks which is dated J287 and the pad stamp is F716CT which means they must of pulled the engine from old stock to use up the inventory for the new block design, and based on what the second owner from '61 told me that they always had overheating issues with the car and he sent out the engine to have it rebuilt and the engine builder found a factory freeze plug left in the engine which caused the issue, my guess is that the block had been put aside after the plug went into the block and when they put it back in production no one knew.
Just my theory. Because it has been documented that these very early '59's used the block, do they still get deductions for the long span between engine cast date and pad stamp, I would like to restore this car to Top Flight level, but am confused on how to proceed with this engine anomaly, any advice would be appreciated since I don't want to invest the time and money in this engine, but on the other hand do not want to throw away a piece of history.
Thanks,
Curt

[Jimmy G.]

Re: Mystery heads

Need casting number on heads Look like 68 heads possibly??

[Curt R.]

Re: Mystery heads

The casting #'s are 3748770 they are the 58 and very early 59 heads, my question is why do they have mounting holes like a passenger car with the X 8 marks for corvette only??

[Cecil L.]

Re: Mystery heads

Because they were used on passenger cars with Level Air suspension.
The X 8 or X58 was not exclusive to Corvette castings.

[Curt R.]

Re: Mystery heads

The dates line up with the engine fairly close , could they have been built with the engine even though they have those accessory mounting holes? Thanks

[Curt R.]

Re: Mystery heads

That's why I am confused, other reports state that heads with machined markings and single digit date code were Corvette only which these heads have! I'm just trying to figure out before I invest on getting them rebuilt with the engine, that these could have been originally installed??

[Patrick B.]

Re: Mystery heads

The Flint foundry did not cast one kind of 770 head for Corvettes and another with the same casting number for regular Chevies. The casting dates of the heads are perfectly reasonable for a July 1958 engine going into a very early 1959 Corvette. What is not typical for a Flint engine is an October 1957 block casting used for a July 1958 engine. Does it still have the original pad stamping?

[Jim L.]

Re: Mystery heads

That's why I am confused, other reports state that heads with machined markings and single digit date code were Corvette only which these heads have! I'm just trying to figure out before I invest on getting them rebuilt with the engine, that these could have been originally installed??

Single digit year casting dates just indicate Flint heads.

All Corvette SBC heads were Flint heads, but most Flint heads were for passenger cars.

[Curt R.]

Re: Mystery heads

Stamp.jpgBlock dates.jpg

[Curt R.]

Re: Mystery heads

In my initial post I explained how this car was #36 off the line and these where the cars that used leftover 3737739 blocks which explains the time lapse between the block casting and the stamp, I also believe that tis block was set aside due to a freeze plug getting punched into the block and when they later used it to finish up that inventory nobody new and that explains why the owner had overheating issues with it. I'm wondering if GM used what they had at the time to since they where also transitioning the heads during that time frame. I don't want to replace the heads or "fill" those holes if they could have been used in this car's application, in other words non-typical, but has anyone seem them used on a very early '59? It seems to me that if someone replaced them at one time for warranty that the dates would be after the build date.