[Tom Vaught]

Blabber Mouth, Paul LOL!

Guys have been playing with spread bore carbs on GM engines for many years.
Remove the Air Horn and you do not have a list number to go by.
The easiest way to tell if the carb is all ORIGINAL and a 800 cfm Spread bore carb
without reverse idle is to look at the pictures attached. You might still be wrong though.

The first picture is the Main Body Idle Circuit drilling.

The second picture is the Idle Circuit for the Reverse Idle Carbs.

So if you "modify" the appearance of the carb slightly you can make the 800 cfm carb into a 650 carb (in appearance). Look at the pictures and post how you would do that.

Tom V.