Our 9” converter is designed to handle nitrous and blowers. Built with a range of stall speeds from 3000 to 4000 RPM stall these converters feature a billet cover made of 4130 steel and Torrington Bearings, their furnace brazed, have a 4130 steel hub and balanced to 5 grams. Art insists on building all converters in-house to ensure quality control and attention to detail.