For the suction lines, I used AN 16 SS oil lines on my 914-6 conversion. For my next motor (going from 3.0 to 3.2
), I am going to have a 90 degree AN 16 fitting connector attached to the end of oil line by the cooler. I prefer to use AN 16 lines since they are aprox the same size as the metric lines that are used on a 911.