Reply With QuoteAre these new heads the aluminum ones you've been talking about? Either way, this is just me talking here, I don't think I'd worry abou the return lines. What you DO want to do is this...
If you are running a set of worked over C's, make sure the drainbacks are drilled out (enlarged) on top and bottom. I'm pretty sure the aluminums have this covered already. No matter how big you make the holes in the heads, you still have to do the block too. This can be done carefully with 2 people. Cover the lifter valley with clean towels, rags or whatever. Have a friend hold the shop vac to suck up the splinters as you drill. I had to do this to mine as it was fully assembled and forgot to do the returns.I run the HV, no restrictors, and a 9qt pan. I haven't had any problems.
_ I just did my Ka's- all four corners, and after running wide open for over 3 minutes at 4800 rpm, my oil pressure never dropped below 70psi with Kendall straight 40wt dino oil. The front return lines weren't even warm, the rear ones were, so I know they are doing their job. I am running a shimmed stock oil pump(blueprinted), and believe it or not, a stock oil pan. I have 60 psi oil pressure at warm idle, 90 till it warms up