When I did the 1.88 in them, the runner was the problem overall.
The numbers, i have downstairs, were peaking around 220cfm iirr. It wasn't max effort... but the amount material removed by hand was enough to scare you away from any max effort w/1.88 in a 318 124cc port.
In the end numbers looked like stock 360...only diff was instead of 160cc it was 137cc iirr.