engine noise
i have this noise with my 360la... i used the same series cam (not sure if its the exact number). I was told you get the "SEWING MACHINE" effect due to the ramp on the cam. When it closes it makes this noise. Do a search on here and you will find posts talking about it.
I was like you and spent a great deal of time checking things over. Well I have around 1k miles on my engine that my brother and I put together last year. It is in my 88' Wrangler and has seen heavy abuse...5k rpm sand hill climbs :)
It could also be the lifters like mentioned as there was talk about comp cams having a batch of bad ones and they had a big call back on them.
I just deal with the noise....turn the radio up or open up the exhaust ..problem solved!!