Tried the search but...

Everybody has their brand preferences whether it be Valvoline, Castrol, Mobil, Royal Purple or what have you. IMHO the brand isnt as important as making sure there is adequate zinc (ZDDP) in it. The ZDDP, which our all knowing EPA mandated be phased out of motor oils is what protects flat tappet cams and lifters. Regardless of the oil I run in any of my flat tappet engines I always put a bottle of zinc additive in it. Rislone makes stuff called Engine Oil Supplement which is a zinc additive. I have used that stuff alot and have yet to wipe a cam using it. I use zinc additives during break in AND driving. Also FWIW, I use conventional oils when I break in an engine. Hope this helps.
It's almost like asking "what underwear should I buy" :D My favorite underwear is Brad Penn 10w-30 with a half bottle of ZDDP additive. I send my oil out all the time to be checked and my zinc numbers are good. Brand Penn is hard to find sometimes but you can order it even on eBay. They manufacture it in Bradford Pennsylvania so it's fairly easy for me to buy a case locally as many people use it around here. Plus they are a smaller oil manufacture so I always like to share my money with the local smaller guys! :cool:

If you really like high levels of zinc, Comp Cams now sells a "break in" oil that you can run all the time even after a break in. They call it a break in oil so they can sell it to the general public without all the EPA restrictions. This way the average Joe doesn't dump it in his new Chevy and melt his cat! I used it for break in oil when I broke in my engine recently and when I had the break in oil tested the zinc was really high. Now too much zinc is also a bad thing as you need some wear, but Comp Cams seems to have come out with this oil for the older flat tappet cam guys so in case you bitch to them about premature cam failure they can say... "well you should have used our oil!" Now someone is making it for them as Comp Cams is not in the oil manufacturing business but it seems to be really good oil. The reason it's more then "break in" oil is due to the fact they sell it in all the different grades.

A lot of guys like the Valvoline racing oil. It's hard to find in the stores but that has high levels of zinc. For the most part buy a case of ZDDP and use your favorite off the shelf oil and dump a bottle of ZDDP in there and you can use anything. Just stay aways from Castrol. It's manufactured by BP and F**K BP as they destroyed our Gulf for the next 70 years!!