Brad Penn oil, Anyone useing it

Just bought a new flat-tappet cam from Isky. They do not like synthetic oils, especially low viscosity index numbers ( ie 0w-15 and 5w-20 ). They feel Brad Penn Grade 1 is the best, but also recommend Valvoline Racing or Pennzoil GTP Racing Oil for flat-tappet cams. The only Synthetic oils they recommend are Amzoil (Red) racing oil or Joe Gibbs Performance Racing Oil for flat-tappet cams.

Valvoline VR1 Racing oil is rated SM/SL/CD, from the back of my VR1 SAE 30 Racing oil.

[ame]http://www.amref.com/CMSFiles/File/bp_pb/7139_40_15_17_BP_PG1_Monograde_HP_Oils_PB.pdf[/ame]

[ame]http://www.valvoline.com/pdf/vr1_racing.pdf[/ame]