Originally Posted by fast68plymouth
First thing I’d do is get a performance calibrated 4160 carb body(like a 3310) and see exactly how the secondary idle ciduit is done on one of those, then duplicate it....... along with using a tunable secondary metering plate.

In the past, when I’ve used those with big cams, I’d just remove the plate and swap to a block...... and then add 4 corner idle.
Which is also what the guy did to the carb in the link.
However, neither of those things are legal for Stock.
i don't think it would be rocket science to duplicate the 3310 or similar design.