Schaeffer 705 20/50 semi
synthetic oil might be worth a look, it has high
zinc and Phos similar to Delo 400, apparently it is good for high performance road cars, has micron moly additive in it as well. Even
Amsoil dont seem to bag Schaeffer
oil in their tests.
I think Rotella has reduced the amount of
zinc but Chevron delo400 15/40 is still the same according to coy reps, which is what I am using initially, but will go onto Schaeffer semi/syn for racing.
Penrite HPR30 has very high
zinc etc is semi
synthetic aussie made
oil, which should be available in the US, the 20/60 weight doesnt do a lot for me as we are colder down here in NZ.
Pennzoil racing 20/50 hasnt as high a zinc/phos rating as the oils I have mentioned but it probably has enough protection.