I was wondering if anyone has used dual pattern turbo flanges before such as a t3 and t4 pattern. Are there any draw backs to the opening size being small for a t4 opening, by the looks the sts one is just a round hole for the t4 and not matched up very well. Another concern is that bolt holes being close to each other and where the two meet there is an area where the nuts are not fully supported, would be something to be worried about. Right now the plans are to use a t3 flange for the turbo that I have will be used, but I was thinking about upgrading in the future and thought using a dual pattern one would give more options.