Ok so I also have a model T and have done research on milling the head using a club in Tulsa or somewhere I don't remember where. Anyways. I milled my Low head to the most they said to mill it to with some improvement but not enough so I ended up installing a Z head on it.
On these "A's " is there enough benefit to milling or not? Not seen the chamber of an A head so I don't know.
On these "A's " is there enough benefit to milling or not? Not seen the chamber of an A head so I don't know.