i am not narrowing it down to just cobra motors. i have a few friends in the import world, and dometic world that have had bearing failures due to thier rp oil breaking down. its just not an oil i would use in a street car. just as wild bill said.
myself, i use mobil 1. mainly because i have used it for years, and a few oem's put it in thier motors straight from the factory. and i check the level VERY religously.
also note, i am not doggin anything other than thier motor oil. i have had thier syncromesh in my t-56 for a few years now and its worked flawlessly.