i have precision 6162
how many millimeters should be the hole oil feed??and return..?2mm feed and 10mm return??thanks!

 

depends on your oil pressure and viscosity of the oil used... every setup is unique, generally start bigger and if you have no oil bypass issues then leave it alone. easy method of tuning oil delivery to the turbo is tap an AN adapter to fit a carb jet so that you can swap them out for smaller jets without much difficulty.

edelbrock jets are usually ideal because they are completely threaded to be inset. versus shoulder set like the holley jets.