I didn't put a zinc additive in during break-in. It's been about 15 years since I last built an engine from scratch and back then no one really knew about how the changes in oil formulations at that time were just beginning to affect zinc levels so it just totally slipped my mind.
As for the oil that was in the engine at break-in, I don't even remember. I think it might have been Castrol, but I don't want to get into a discussion about oil brands. As far as I can tell, as long as you use the correct weight and change it regularly it really doesn't matter what brand you pour in there so I just buy whatever's on sale. I've always dumped the oil right after the initial 15-20 minute run-in, then again in ~50 miles and then again after about 500 miles then at regular change intervals.
That said, an oil like Valvoline VR1 (or the Joe Gibbs mentioned above) is formulated differently from standard passenger car oils and has higher levels of zinc like all oils used to have. Guess I'll just replace the cam and rockers and buy a case of zinc additive to put in at each oil change from here on out. One positive - I kind of wanted a little bigger cam anyway. This one's all about the bottom-end torque...