i haven't read your link explaining the original problem but one thing that might be worth looking into is oil pump related, you mentioned that the engine has been over hauled. If the previous owner did build it himself he may not have replaced the oil pump and not only that how many people here have seen engine an engine built with enough silicone sealant floating around the sump to seal most peoples bathrooms up? all that gets stuck to the syphen pick up and prevents enough oil flow. We all know on here that psi is good but its volume that counts?