408 tuning with a Wideband sensor

I finally fixed the oil leak! Once I replace the clutch disc because it won't hold the stroker's brute force anymore, I'll be able to start tuning under heavy load. Anyone want to buy a slightly used centerforce disc?? I think it would hold up to a mild small block. Which holes are the idle feed restrictors? I've heard of doing this before by inserting a small diameter wire in them to reduce the area.