The V8 Owners Forum -

I had the same problem on my rv8,lots of oil in the head after using aftermarket rockers(the oil grooves are too deep in them)at idle I had 14 psi oil pressure, so I got some brake pipe(which happens to have the same dia as the oil hole in the head)and tapped it in thus reducing the oilway to about ...

i have a 4.6 "thor" lump which had exactly the same issues as yours,perfect compression etc.turned out that the oil control rings were so worn that you didn't need a ring compressor to reassemble them back into the block.