[Eightupman]

Originally Posted by joe_padavano

Sorry John, but I must again disagree with this line of reasoning. C heads were cast in the 1967-1969 model years, but the federal requirement for low-lead gasoline did not come into effect until the 1971 model year. There would have been no reason to build C or CA heads with hardened seats. Similarly, since it WAS a federal requirement to run on low-lead starting with the 1971 models, even the G and H heads came with hardened seats. Also, what about no. 8 heads? Since there was never an 8A, your logic would indicate that all no. 8 heads do NOT have hardened seats. That is not correct.

Olds used the "A" to indicate a minor casting change. That's why we have F and FA blocks, for example.

Reread what I typed Joe. I stated that all #8 heads have hardened seats, therefore debunking my own logic.

John