These T4 flanges are absolutely a must have for anyone building a turbocharger setup. Mounting and properly supporting your turbo is essential to longevity of the expensive investment of a turbo system. If you have ever mounted a turbo without this mount you will know it is no easy task and building a mount without interfering with piping or running into the turbo housing is no easy task. Our turbo flanges are CNC laser cut from 1/2" mild steel to make for a very durable and sturdy platform for your turbo to mate to and be supported and at a price that is the same or less than a standard flange. The mounting ears as seen in the pictures have 3/8" through holes. These flanges are compatible with both split and non split turbo flange setups including but not limited to Precision Turbos, Garrett Turbochargers, Borg Warner Turbos, Turbonetics, Master Power, and many more S400, S500, Pro Mod, GT55, GT42. Many people these days are doing LS1 or LSX turbo swaps and room is tight so make sure to make mounting easy for yourself.