I've seen recommendations for 10w30, 10w40, straight 30, and either VR-1 or Rotella, or your favorite brand with zinc additive. Some say 5 quarts, some seem to say 6 qts. No question on the filter, I will use a Motorcraft FLA1.
Couple of questions, I assume 10w30 would be better for a tight motor and 10w40 for an older build? Is straight 30 more for the nostalgic motor head or valid reasoning?
Would one be better off running VR-1 (synth or non -synth) 10w30 by itself, or something like Motorcraft 10w30 synth-blend with a bottle of Lucas Oil zinc? If adding zinc, is it 1 bottle + 5 or 6 qts. or do you pull the oil quantity down equivalent to the amount of zinc to be added?