No CNC machining
Most are done with hand held tools
I've seen one member use a die grinder to cut the intake carburetor mount down to where it opens up
Another example:
Thanks for the replies, it sounds like I have a "hex" log.
Some background on what I want to do. Right now my van is sporting the Holley 1940 carb that was on the 170 engine the van came to me with. It runs the engine, but not very well. I have some 2G carbs and the one I want to use is the black one in the photo:
This is the carburetor (left) I bought from Ebay. It’s referred to as a Mercarb and similar to a Rochester 2G, but has some differences. This is the smaller unit for the 120/140 Hp engines as evidenced by the smaller throttle bores. You can see there is...