Does anyone know what the BG suffix means on a '64 330 head? The stamped number on the right head is T210503BG (with the B over the G). It's a 4 bbl, dual exhaust, early (rocker shafts), engine with a stick crank. I can find the G suffix listed as "High Compression", but no reference to the BG combo.

 

That is not a factory stamp. Likely the heads were done at one time and the machine shop did that.

 

Pretty sure these are factory stamps. There should be a suffix and had the "G" been there on it's own it would line up with the numbers but it has been lowered half way down to fit the "B" above it. Also, everything is appears to be lined up, the same depth, and the same type.

I'll try to post a picture and you will be able to see what I mean. I can't get my computer to take the pictures off my phone for some reason. I have to figure out what that problem is.

 

I figured out how to get a picture here.