<VV> Engine oil again

[shortle]

Dear All in VV land,
   Just a question regarding actual brand name oil. As a foreign car mechanic/technician (Volvo only) since 1981, I have been using Castrol GTX 10w30 in my customers cars since day 1.
   I contacted Castrol recently and they said this oil would be fine in my Corvairs.What is the general thinking on this oil. The latest engine I am using this on is in my 1963 FC Rampside 164CI 95HP PG.
   And I thank you all for the feedback. I hope I am not beating a dead horse but all I see is talk on ZDDP but very few brand names mentioned.
Timothy Shortle in Durango Colorado.