One way to insure you are getting oil to the lifters is pull one of the front lifters and your distrubutor and get an oil pump priming tool for your drill. Run your oil pump with your drill and look for good oil flow to your lifter down the lifter bore. I friend of mine had one rocker that wouldn't get any oil, we did what I mentioned above and found the lifter to be getting good oil. It turned out the lifter was bad. What kind of lifters do you have, he had edelbrock and I know of another person who had edelbrock and both would pump up or allow oil to flow through the lifter. Wonder if edelbrock has a quility control problem with these lifters?