Just a sticky note for people that are building a new World/Mopar Iron Wedge block and Edelbrock RPM heads. The oil drain back holes in the heads are completely blocked by the beefy/additional cast iron in the valley. Im helping a friend with his 540" street engine and ran into this when I was setting the heads on. Im fairly certain that grinding or drillng the block in that area wont be a problem, but I will sonic it first. This wouldnt be an issue if I knew about it up front. No biggy...live an learn. I really like these blocks, but dealing with the little fitment issues vs. a stock block are interesting to say the least. Im kinda bummed because I already have the long block assembled when I noticed this. DOH!!!!! Everything else went smooth. Im using hydraulic roller lifters from Comp and they clear the valley unlike many other manufacturers roller lifter link bars. Crower is working on a new lifter that has a taller link bar and its supposed to be ready in a few months. Again, the block is extra beefy in the valley, which adds to the complications of fitting parts that normally fit a stock block.
Anyways, Im not complaining at all, just giving other people a heads up before assembling your engine yourself. Just a few things to look at. I know the majority of engine builders on this forum already know about this as they had to find out when these blocks came out, but for the guys that build their own engines this info could save some time and headaches.