Oil return flange broke, it is aluminum. All these usually same size ? I keep finding 1/2 NPT but not sure if that what I have or not.

Where is a good place to get these from are they usually the right size, meaning the bolt hole distance etc if it fits a T3/T4 hybrid ??

 

Yes. Most of these are aluminium, but it looks like that cracked developed from using a brass fitting that wasn't a proper match thread for that flange, or used too much force. If you want to be sure of the fitting , please measure the thread pitch & diameter exactly (as best you can), so that any new flange you get (which is about 1/2NPT, but not all will be exact), to make sure that your brass barbed wire fitting works.

For Journal bearing Garrett/Precision/Turbonetics turbochargers, what you have looks about right. They are both made in male and female flange styles