In fact if you read the literature that comes with Comp cams it states that the warranty is void if you do NOT use Comp Break-in oil. And yeah it is very important that the engine fires up right away.
I'm working on a young friend's 351W for his 69 FB Torino and he bought a Thumpr cam so that's how I know. (also Trick-Flo heads) Last time I was in the Summit store, I bought the Comp oil for his engine cause I don't want to screw it up.