Originally posted by inspyral
You plug the orifice and then run a line from the back of the block(usually the oil pressure sender) to the head. The head has a pre-existing hole that is plugged from the factory. You remove the plug and screw in an -AN fitting adapter to run the oil line. I suspect the oil orifice in the VTEC heads don't line up perfectly with a flat surface on the non-VTEC blocks, so you wouldn't want something like coolant from the water jacket making its way in there.
I see. The reason I asked is because I have two blocks that I just got back from Import Builders. One is a GSR build, so it doesn't matter, the other is an LS build. I noticed on the LS block that the orifice hole is plugged there with an 1/8npt plug. Just wondering if this would suffice or would you have to plug the head as well.
Thanks,