What's the difference between the ECZ-C heads, and the ECZ-G heads? I am fairly sure both types of heads came off of a 292, but I am still learning about the Y-block.

The port size and the intake valve size is larger on the ECZ-G heads. The chamber shape on the ECZ-G head includes an overhanging lip.



Many builders are happy to use the ECZ-C heads. The chambers are pretty close in size so the compression ratio is similar. The intake valve on the -G heads is 1.92, the intake on the -C heads are 1.72. You can install a 1.84 valve on the -C heads and do some pocket porting to help out with its flow.

Best regards,



Paul Menten

Meridian, Idaho

Another difference will be that all the ECG-C heads will be of the unposted variety while the ECZ-G heads made later in the production run of those particular heads will be posted.

Here’s more on posted heads and how to identify.

http://www.y-blocksforever.com/forums/Topic6711-3-1.aspx

Lorena, Texas (South of Waco)