Welcome to the Stovebolt! Here is a link to the dtfferent features of these old Chevy Chevy Sixes Picture 10 shows the device that only exists on low pressure versions.

I like to run an engine to see it and hear it, before I tear it down. That way I have an idea what I am working with.

1951 GMC 1 Ton Flatbed -- It is finally on the road and what a great time I have driving it!
1951 1 Ton Completed

My Chevy Master 4 Door is on the Road!