I've found that most T3's don't have the seal between the compressor housing and the backing plate. Many just spray a thin layer of copper RTV on to make a seal or the like.

On turbomustangs.com, I've been reading up on very simular situations where they're smoking. Most people run atleast a 5/8"/-10AN oil return line to stop issues like mine. They also atleast run a -3AN or -4AN feed line with a restrictor, which I do have.

How large of an I.D. return line do you all run? Mine is 1/2" copper with high temp hose ends simply to adapt it to my fittings with hose barbs.

On top of getting the missing gaskets, I'm considering ditching the hose fittings and get down to the pipe thread to -AN adapters, bore them out to as big of an I.D. as I can, and build a new solid return line that's 5/8" or 3/4".

2005 Ford F150 SuperCab FX4 1964 Chevrolet Impala SS 1998 CSVT: 354HP/328TQ @ 10 psi, now gone