Something you might want to check is the EGR tube. Mine didn't seal properly after reinstalling things, and I picked up a really weird kind of clattery sound that wasn't always present, but most often was. Once I resealed the EGR tube properly all was well.

 

check the opti, friend did a cam on his 94Z, had detonation, ripped it all down, checked everything over, ran it half apart, was fine, put it entirely together, detonating again.

end result? the opti was overtorqued when it was reinstalled and cracked the housing, that let moisture in and boom...there's the detonation.

would only detonate when you got on it hard, if you rev'd it easy up to redline, no pinging.