3748770 cylinder heads

[Jack C.]

Just returned from Wisconsin with a (so-called) numbers-matching engine for my 1958 which has an approximate build date of December 26, 1957. The 3748770 heads that are installed on the engine have casting dates of L 5 7 (December 5, 1957) and L 6 7 (December 6, 1957). From all visual indications the casting number and dates have not been tampered with and are evenly spaced with the screw heads relatively close to the L and the 7. However, neither head has the traditional X-58 casting on the side of the head which every reference book references on heads casted at Central Foundry in Saginaw.

Does anyone know what I've got? Has anyone seen 770 heads from Saginaw without the X-58? Any help will be appreciated.

[Tom D.]

Re: 3748770 cylinder heads

If there are three holes in the end of the head, drilled for brackets, it's not a Corvette head.
This is from Mr. Alan Colvin's boook, available on this web site (NCRS.ORG) - There is more on page 75 of the 1955-1959 segment of these books, called "Chevrolet By the Numbers". My copy is dated 1996 - Don't know if there is a later edition.

Tom Dingman
4889

[Jack C.]

Re: 3748770 cylinder heads

Tom,
I re-examed the heads and there are no existing holes in the ends or any indication that any holes previously existed and have been filled. I also have a copy of Alan Colvin's book and also the 1958-60 NCRS Judging Guide which both reference the "X-58" on side of head. My concern is that with both those sources referencing the X-58 will those heads be rejected for NCRS judging?

Do you have any suggestions on who and how to contact an authority in the 58-60 NCRS judging area to get a definitive answer on the judging issue?

Thanks for your response and assistance.
Jack

[Jack H.]

Re: 3748770 cylinder heads

"Do you have any suggestions on who and how to contact an authority in the 58-60 NCRS judging area to get a definitive answer on the judging issue?"

Questions like these are best addressed to the cognizant National Team Leader... Your copy of the NCRS Restorer Magazine lists phone/email contacts for all of the NTL's and judging authorities.