They definately like more air then less, I normally run a hole around 4-5mm for that size stick to get them idling how i like and end up around...6gm/s with a dead smooth idle at 800 rpm and 13.5-14 afr, 15 degrees timing (no correction) and zero lope. That size hole wont cause you any dramas if u set max idle air up correctly and min idle air. Twin turbo stuff with stock cams I drill 3mm holes to help the surging at idle and pulsing by the compressors.
You will find they like more air then less. My 248-254-106(admittly a carb) using stock pcm for spark idles at 20 degrees timing at 800rpm and NO spark correction, And it idles like a 224-228 would in LS1 terms at 14:1 afr and idle very smooth. The trick to this is consistent idle spark and airflow. Any changes in airflow and spark will disrupt the idle to a degree and cause it to hunt up and down by 50-100rpm. My carb has a 4mm hole drilled in each butterfly (yes four of them) so they sit in the correct position with 40 thou of the transfer slot exposed. My TK cam had an 8 mm hole in the TB I had to keep going bigger with the airflow "maxxed out".
I still prefer the original method of maxxing out max idle air. I can arrive at the point a lot faster. The integral correction is still taking place otherwise I try to eliminate that. The amazing thing is if you "lock out" the air you can then push the timing up and down(with no correction) while datalogging and engine running, I keep the air fuel in the high 13s and then raise the spark up and down until I get the best idle vacuum. In most cases then I run very minor correction in both timing and throttle like -3 deg max for timing and 0.080 for integral as a max number. Thats how I get them with a standard idle. Usually at the drags/etc combined with varex mufflers it passes as a 100% stock engine at idle. Fuel economy drastically improves around town and it really passes as a stock car to drive, Most people even if they love a tough sounding engine always go this way as it is so much better to drive. Most tuners just try to get the car driving and eliminate hunting and stop there. Go beyond that. Lock airflow, adjust timing with DVT. get in open loop Note down the max idle air, and adjust timing, increase air try different timing again. Once you arrive there establish min idle air and get the corrections to a minimum with a bypass in the TB. Cold start and drivability it all goes hand in hand.
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