valve train rocker arms

[Irvine47]

I purchased our 57 and went to adjust the valves and one side had the rockers that you use a screw driver and a lock nut and the other side was the one you use a wrench on. One of my friends told me that the 312 rockers for the Thunderbird was different than what the Ford passenger car had, is this true? May I ask what the part # is for the correct Thunderbird rocker?

[Harley Eaton]

According to the Official Ford Parts book 1949-1959, all Ford passenger cars and Thunderbird, 1952 thru 1957 with 239, 272, 292, 312 engines use C0AZ-6564-A rocker arms.

[paul2748]

Originally Posted by Harley Eaton

According to the Official Ford Parts book 1949-1959, all Ford passenger cars and Thunderbird, 1952 thru 1957 with 239, 272, 292, 312 engines use C0AZ-6564-A rocker arms.

Not true. First of all, 52 and 53 did not have rocker arms - the engines were a flathead. There were two rocker arm ratios used over the years. The 57's and 58's used the high ratio rocker arms, the rest of the years used the other one as far as I know. They also had two different styles for adjustment as the writer has noted.

The COAZ came out in 1960 and is probably a replacement. All replacement were the lower ratio rocker.

[paul2748]

Besides the two different methods for adjusting, YBlocks also had two different ratios. 57 had the high ratio rockers. I think that the different methods of adjustment pertain to different years, not different models. I don't remember which years had which.

The correct rocker for 57 had ECG-6564 A2 (or B2) for a casting number. These were the high ratio ones. The low ratio ones had just a number of 6 or 7 digits The only place I know where to get the correct rockers is John Mummert 619-596-0312. John can tell you what years had which method of adjustment.

Originally Posted by Irvine47

I purchased our 57 and went to adjust the valves and one side had the rockers that you use a screw driver and a lock nut and the other side was the one you use a wrench on. One of my friends told me that the 312 rockers for the Thunderbird was different than what the Ford passenger car had, is this true? May I ask what the part # is for the correct Thunderbird rocker?

[Harley Eaton]

Excuse me Paul... My statement was : "According to the Official Ford Parts Book -----". You are trying to say this is incorrect?

[paul2748]

Yes - It is wrong - Ford parts books listed the replacement part as of the date is was published, not the original part. Just looking at the number shows is a 60's casting number. Are you saying that Ford engines had rocker arms in 52 and 52 (Lincoln's and 6 cylinders excepted- I don't think the V8's used the 6's rockers or the Lincoln's as it was a whole different engine)

Originally Posted by Harley Eaton

Excuse me Paul... My statement was : "According to the Official Ford Parts Book -----". You are trying to say this is incorrect?