identifying 550 heads

[Stephen R.]

I have a quick question regarding the date code on the #550 heads. Is a 550 head with a date code of A 14 59 not a correct application for a corvette engine? Would this be a Tonawanda/passenger car head?
Thanks

[Stewart A.]

Re: identifying 550 heads

550 heads were an early 59 head, 770 was 58 and very early 59. 465 was a late 59 head. I have no idea when the change over was. I know the 1960 692 head has a machined finish on the symbol and the rough cast was Tonawanda head. I am not sure if the date tells you that it's a Tonawanda head. Someone might want to jump in on this one and explain better. I think the head you have is correct. Although it is really early being a mid Jan head ? Stewy

[Joe L.]

Re: identifying 550 heads

I have a quick question regarding the date code on the #550 heads. Is a 550 head with a date code of A 14 59 not a correct application for a corvette engine? Would this be a Tonawanda/passenger car head?
Thanks

Stephen-----


The 2 digit year code indicates a Tonawanda-cast head which were not used on Corvettes. A large, raised "T" found anywhere on the casting will confirm that although I don't know that all Tonawanda castings had the "T".

[Bill M.]

Re: identifying 550 heads

I have a quick question regarding the date code on the #550 heads. Is a 550 head with a date code of A 14 59 not a correct application for a corvette engine? Would this be a Tonawanda/passenger car head?
Thanks

Stephen:

Two more things to look for on a Flint (one digit year code) 550 head:

I've heard that the passenger car heads had holes drilled in the end of the head to mount accessories. (I've never seen one.) I guess you could fill them...

There is a set of 550s on ebay that don't have the spark plug cooling holes drilled. This is a new one for me. I don't know what that means...yet.

Bill

[Stephen R.]

Re: identifying 550 heads

That Ebay guy is what prompted my question. I have a March 59 build date Vette and a partially built engine in the basement. The heads he has for sale are A 14 59 and otherwise look correct. The date would be perfect for my car, but apparently the double digit date is not correct for a Vette engine. Thanks for the info. Saved me some money.

[Ian G.]

Re: identifying 550 heads

Like Stewy mentioned, Tonawanda did not machine the square with pyramid symbol on the end of the head. I believe that was machined to provide clearance for the engine crossmount to tightly torque down the water pump. Also, you want to be careful of the staggered vs. parallel valve cover bolt pattern which changed over in May as mentioned in the JG. Early 550 heads are staggered, which was what I needed for my 12/58 build date.