1955 Patrician 352 oil recommendations

Posted by Packman 1955 On 2023/10/8 20:31:13

Hello all, I am completely tearing down and trying to clean my Patrician 352. There was a lot of sludge and dirt. Engine has around 38,000 miles and appears to be original shape. I am disassembling the hydraulic lifters and trying to get any and all old sludge or oil deposits out. I have been trying to research correct oil replacement for the straight 20W per manual. I live in central PA and car will be started from time to time in the winter to circulate fluids. I was wondering if a synthetic 5w20 would be too low of a viscosity oil to use. I am planning on changing to the Mellon oil pump as well, unless I would lose important vacuum features as the wipers or anything drastic. I am also replacing new seals and figured a synthetic would be fine then. Was thinking of Valvoline or Castrol. Thanks for anyone's input or expertise on this. I wanted to figure out what to use so I can fill the lifters before re-assembly.