All I did on mine was round/smooth the runner sides and roof of each from the plenum junction, and port matched and smoothed the runner roofs about 1-1/2" in. Smoothing and rounding, not really enlarging (other than the gasket match) is easy, and safe I'd say, and when you study that intake you'll easily see where the work needs to be done. I leaned heavily on David Vizard articles and others about typical proven results from simple clean-up of intakes without getting into extensive porting.
