I have a 435hp 427 the number on the motor is To709lr then 19s725170. I have the wrong heads on the motor and want the correct ones would these be correct and worth it. DATE CODES I 26 8 ......D 3 8 HEADS ARE 3919840 .

 

those are the correct heads for a 427 435hp engine on a 68 or 69. I can't help you with the date code yet, i'm still looking on the net for ya.

Jim


OK here is what i found.
Cylinder Head Casting Date:
The cylinder head casting date is usually found adjacent to the cylinder head casting number. The casting date code is an alphanumeric sequenced number. The first digit is usually a letter which specifies the month that the block was cast. Some casting dates have been found with all digits being numbers, the first of which corresponds to the month.

Cylinder Head Casting Number Month Codes (1st Digit)
A - January E - May I - September
B - February F - June J - October
C - March G - July K - November
D - April H - August L - December

Two main plants were casting Chevrolet engine parts during 1968: Flint, Michigan and Tonawanda, New York.

Example: Flint Cylinder Head Casting Number - D 19 9


D: Month = April
19: Casting Day = 19th
9: Casting Year = 1959

Example: Tonawanda Cylinder Head Casting Number - D 19 59


D: Month = April
19: Casting Day = 19th
59: Casting Year = 1959


So your heads were SEPT 26th 1968

Here is where i found the Information.
http://www.corvetteactioncenter.com/...1968/68id.html

Are they worth it?...it's up to you. I spent over 700.00 on a correct numbered carb on my 71 454... it was worth it to me since the rest of the car it dated correctly and it only has 40k miles on it. I guess it depends on how the rest of the car is put together and how original it is.
But for correct date code it has to be up to 6 months before the cars assembly date.

Hope this helps,
jim

 

I'm assuming by your vin and engine suffix that your car is a 69 built in July. The heads are the correct casting but not the correct date. The heads should be just a few weeks earlier than the engine build 0709 (July 9, 69). I think up to 6 months is acceptable for NCRS but usually more like 2 to 6 weeks. I'm sure some NCRS experts can answer better.

 

Thanks for all your help. Why buy them if they aren't right. If you know anyone with the correct parts and date codes, need heads, tripower and exhaust manifolds please let me know. One last thing did this car come with a smog pump?

 

I don't think it came with a smog pump but I'm not sure. I know more about 70-72. That's not only because I've owned 2 70s and a 71, but more importantly I bought the NCRS Technical Information Manual. If you care about how your car came originally from the factory, there's no better book to own. Go to NCRS.org and buy one. It's well worth the money.