My 59 235 has good oil pressure. When I drive for a distance (a couple miles)the lifters start to rattle under load,climbing etc. When I let up and coast they quiet down.When it starts rattling the oil pressure still reads 30.when it gets real bad it starts to go down to about 15,but not as a rule.Some times the day after a long drive it will rattle at startup and stay rattling until the oil gets to the lifters and then it quiets down. The pickup screen is ok,the pressure is good so I don't think it's the pump. I'm guessing that for some reason the oil is restricted from reaching the lifters.I plan on removing the oil pan and valve cover this weekend and do a search. What should I look for?I will remove the pump and visually inspect it as well as the pickup tube.I heard something about a head bolt that is drilled for oil passage on some of these.Is this on my engine? Where would I find it? I really need help here. I am driving this every day but only short trips. I'm afraid I'm going to ruin this rebuilt engine. Help!---Jack
