I got a 99 350 that I got hot, cracked heads. So Im on way bak together now but I was. doing the valve lash and noticed something odd. I did them all once rolled the engine back to tdc and the push rods was a little loose again, so I adjusted them again and, rolled it over to next set of valves and again loose. So adjusted them again and back to tdc and they was loose again, did this about 5 times until they stopped loosening up.does this sound right or what should I do.